intern/cycles/scene/volume.cpp

@@ -506,7 +506,8 @@ static int estimate_required_velocity_padding(openvdb::GridBase::ConstPtr grid,
   openvdb::math::Extrema extrema;
   openvdb::Vec3d voxel_size;
 
-  /* External .vdb files have a vec3 type for velocity, but the Blender exporter creates a vec4. */
+  /* External `.vdb` files have a vec3 type for velocity,
+   * but the Blender exporter creates a vec4. */
   if (grid->isType<openvdb::Vec3fGrid>()) {
     openvdb::Vec3fGrid::ConstPtr vel_grid = openvdb::gridConstPtrCast<openvdb::Vec3fGrid>(grid);
     extrema = openvdb::tools::extrema(vel_grid->cbeginValueOn());

intern/ghost/GHOST_C-api.h

@@ -475,11 +475,11 @@ extern void GHOST_setNDOFDeadZone(float deadzone);
 #endif
 
 /***************************************************************************************
- * Drag'n'drop operations
+ * Drag & drop operations
  ***************************************************************************************/
 
 /**
- * Tells if the ongoing drag'n'drop object can be accepted upon mouse drop
+ * Tells if the ongoing drag & drop object can be accepted upon mouse drop.
  */
 extern void GHOST_setAcceptDragOperation(GHOST_WindowHandle windowhandle, bool can_accept);
 

intern/ghost/GHOST_IWindow.hh

@@ -139,7 +139,7 @@ class GHOST_IWindow {
   virtual void clientToScreen(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const = 0;
 
   /**
-   * Tells if the ongoing drag'n'drop object can be accepted upon mouse drop
+   * Tells if the ongoing drag & drop object can be accepted upon mouse drop
    */
   virtual void setAcceptDragOperation(bool canAccept) = 0;
 

intern/ghost/intern/GHOST_EventDragnDrop.hh

@@ -18,16 +18,16 @@
  * The dragging sequence is performed in four phases:
  *
  * - Start sequence (GHOST_kEventDraggingEntered) that tells
- *   a drag'n'drop operation has started.
+ *   a drag & drop operation has started.
  *   Already gives the object data type, and the entering mouse location
  *
  * - Update mouse position (GHOST_kEventDraggingUpdated) sent upon each mouse move until the
- *   drag'n'drop operation stops, to give the updated mouse position.
+ *   drag & drop operation stops, to give the updated mouse position.
  *   Useful to highlight a potential destination, and update the status
  *   (through GHOST_setAcceptDragOperation) telling if the object can be dropped at the current
  *   cursor position.
  *
- * - Abort drag'n'drop sequence (GHOST_kEventDraggingExited)
+ * - Abort drag & drop sequence (#GHOST_kEventDraggingExited)
  *   sent when the user moved the mouse outside the window.
  *
  * - Send the dropped data (GHOST_kEventDraggingDropDone)

intern/ghost/intern/GHOST_SystemCocoa.hh

@@ -140,8 +140,8 @@ class GHOST_SystemCocoa : public GHOST_System {
   bool handleOpenDocumentRequest(void *filepathStr);
 
   /**
-   * Handles a drag'n'drop destination event. Called by GHOST_WindowCocoa window subclass
-   * \param eventType: The type of drag'n'drop event.
+   * Handles a drag & drop destination event. Called by GHOST_WindowCocoa window subclass.
+   * \param eventType: The type of drag & drop event.
    * \param draggedObjectType: The type object concerned.
    * (currently array of file names, string, TIFF image).
    * \param mouseX: x mouse coordinate (in cocoa base window coordinates).

intern/ghost/intern/GHOST_SystemWin32.hh

@@ -264,9 +264,9 @@ class GHOST_SystemWin32 : public GHOST_System {
                                 GHOST_DialogOptions dialog_options) const;
 
   /**
-   * Creates a drag'n'drop event and pushes it immediately onto the event queue.
-   * Called by GHOST_DropTargetWin32 class.
-   * \param eventType: The type of drag'n'drop event
+   * Creates a drag & drop event and pushes it immediately onto the event queue.
+   * Called by #GHOST_DropTargetWin32 class.
+   * \param eventType: The type of drag & drop event
    * \param draggedObjectType: The type object concerned
    * (currently array of file names, string, ?bitmap)
    * \param mouseX: x mouse coordinate (in window coordinates)

intern/ghost/intern/GHOST_SystemX11.hh

@@ -246,9 +246,9 @@ class GHOST_SystemX11 : public GHOST_System {
                                 GHOST_DialogOptions dialog_options) const override;
 #ifdef WITH_XDND
   /**
-   * Creates a drag'n'drop event and pushes it immediately onto the event queue.
-   * Called by GHOST_DropTargetX11 class.
-   * \param eventType: The type of drag'n'drop event.
+   * Creates a drag & drop event and pushes it immediately onto the event queue.
+   * Called by #GHOST_DropTargetX11 class.
+   * \param eventType: The type of drag & drop event.
    * \param draggedObjectType: The type object concerned.
    * (currently array of file names, string, ?bitmap)
    * \param mouseX: x mouse coordinate (in window coordinates).

intern/ghost/intern/GHOST_Window.hh

@@ -200,7 +200,7 @@ class GHOST_Window : public GHOST_IWindow {
   GHOST_TSuccess getSwapInterval(int &intervalOut) override;
 
   /**
-   * Tells if the ongoing drag'n'drop object can be accepted upon mouse drop
+   * Tells if the ongoing drag & drop object can be accepted upon mouse drop.
    */
   void setAcceptDragOperation(bool canAccept) override;
 
@@ -401,7 +401,7 @@ class GHOST_Window : public GHOST_IWindow {
   /** The presence of progress indicator with the application icon */
   bool m_progressBarVisible;
 
-  /** The acceptance of the "drop candidate" of the current drag'n'drop operation */
+  /** The acceptance of the "drop candidate" of the current drag & drop operation. */
   bool m_canAcceptDragOperation;
 
   /** Modified state : are there unsaved changes */

intern/ghost/intern/GHOST_WindowCocoa.mm

@@ -172,7 +172,7 @@
   return (associatedWindow->isDialog() || !systemCocoa->hasDialogWindow());
 }
 
-/* The drag'n'drop dragging destination methods. */
+/* The drag & drop dragging destination methods. */
 - (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender
 {
   NSPoint mouseLocation = [sender draggingLocation];

intern/ghost/intern/GHOST_WindowWin32.cc

@@ -44,7 +44,7 @@
 const wchar_t *GHOST_WindowWin32::s_windowClassName = L"GHOST_WindowClass";
 const int GHOST_WindowWin32::s_maxTitleLength = 128;
 
-/* force NVidia Optimus to used dedicated graphics */
+/* force NVidia OPTIMUS to used dedicated graphics */
 extern "C" {
 __declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001;
 }

intern/ghost/intern/GHOST_XrGraphicsBinding.cc

@@ -465,7 +465,7 @@ class GHOST_XrGraphicsBindingD3D : public GHOST_IXrGraphicsBinding {
 #  if 0
     /* Ideally we'd just create a render target view for the OpenXR swap-chain image texture and
      * blit from the OpenGL context into it. The NV_DX_interop extension doesn't want to work with
-     * this though. At least not with Optimus hardware. See:
+     * this though. At least not with OPTIMUS hardware. See:
      * https://github.com/mpv-player/mpv/issues/2949#issuecomment-197262807.
      */
 

scripts/startup/bl_operators/view3d.py

@@ -147,7 +147,7 @@ class VIEW3D_OT_edit_mesh_extrude_move(Operator):
                     # Don't set the constraint axis since users will expect MMB
                     # to use the user setting, see: #61637
                     # "orient_type": 'NORMAL',
-                    # Not a popular choice, too restrictive for retopo.
+                    # Not a popular choice, too restrictive for retopology.
                     # "constraint_axis": (True, True, False),
                     "constraint_axis": (False, False, False),
                     "release_confirm": False,

scripts/startup/bl_ui/space_view3d.py

@@ -904,6 +904,8 @@ class VIEW3D_HT_header(Header):
 
             if object_mode == 'PAINT_GPENCIL':
                 row = layout.row(align=True)
+                sub.prop(tool_settings, "use_gpencil_draw_onback", text="", icon='MOD_OPACITY')
+                sub.separator(factor=0.4)
                 row.prop(tool_settings, "use_gpencil_draw_additive", text="", icon='FREEZE')
 
             if object_mode in {'PAINT_GPENCIL', 'EDIT', 'SCULPT_GPENCIL', 'WEIGHT_GPENCIL'}:

source/blender/blenkernel/BKE_screen.hh

@@ -143,9 +143,6 @@ struct SpaceType {
   /* region type definitions */
   ListBase regiontypes;
 
-  /** Asset shelf type definitions. */
-  blender::Vector<std::unique_ptr<AssetShelfType>> asset_shelf_types;
-
   /* read and write... */
 
   /** Default key-maps to add. */
@@ -534,6 +531,9 @@ struct AssetShelfType {
 
   int space_type;
 
+  /** Operator to call when activating a grid view item. */
+  std::string activate_operator;
+
   AssetShelfTypeFlag flag;
 
   short default_preview_size;
@@ -552,6 +552,8 @@ struct AssetShelfType {
                             const blender::asset_system::AssetRepresentation *asset,
                             uiLayout *layout);
 
+  const AssetWeakReference *(*get_active_asset)(const AssetShelfType *shelf_type);
+
   /* RNA integration */
   ExtensionRNA rna_ext;
 };

source/blender/blenkernel/intern/writeffmpeg.cc

@@ -1380,8 +1380,7 @@ static bool start_ffmpeg_impl(FFMpegContext *context,
       break;
     default:
       /* These containers are not restricted to any specific codec types.
-       * Currently we expect these to be .avi, .mov, .mkv, and .mp4.
-       */
+       * Currently we expect these to be `.avi`, `.mov`, `.mkv`, and `.mp4`. */
       video_codec = context->ffmpeg_codec;
       break;
   }

source/blender/blenlib/intern/delaunay_2d.cc

@@ -1905,7 +1905,7 @@ void add_edge_constraint(
    * Fill crossings array with CrossData points for intersection path from v1 to v2.
    *
    * At every point, the crossings array has the path so far, except that
-   * the .out field of the last element of it may not be known yet -- if that
+   * the `.out` field of the last element of it may not be known yet -- if that
    * last element is a vertex, then we won't know the output edge until we
    * find the next crossing.
    *

source/blender/blenlib/intern/math_color.cc

@@ -306,7 +306,7 @@ void rgb_to_hsv_compat(float r, float g, float b, float *r_h, float *r_s, float
   rgb_to_hsv(r, g, b, r_h, r_s, r_v);
 
   if (*r_v <= 1e-8) {
-    /* Very low v values will affect the hs values, correct them in post. */
+    /* Very low V values will affect the HS values, correct them in post. */
     *r_h = orig_h;
     *r_s = orig_s;
   }

source/blender/blenlib/intern/mesh_boolean.cc

@@ -615,7 +615,7 @@ class CellsInfo {
 };
 
 /**
- * For Debugging: write a .obj file showing the patch/cell structure or just the cells.
+ * For Debugging: write an `.obj` file showing the patch/cell structure or just the cells.
  */
 static void write_obj_cell_patch(const IMesh &m,
                                  const CellsInfo &cinfo,

source/blender/blenlib/intern/string_utils.cc

@@ -284,7 +284,7 @@ size_t BLI_string_flip_side_name(char *name_dst,
   /* always copy the name, since this can be called with an uninitialized string */
   len = BLI_strncpy_rlen(name_dst, name_src, name_dst_maxncpy);
   if (len < 3) {
-    /* we don't do names like .R or .L */
+    /* We don't support names such as `.R` or `.L`. */
     return len;
   }
 

source/blender/draw/engines/eevee_next/eevee_instance.cc

@@ -455,8 +455,8 @@ void Instance::render_read_result(RenderLayer *render_layer, const char *view_na
       BLI_mutex_lock(&render->update_render_passes_mutex);
       /* WORKAROUND: We use texture read to avoid using a frame-buffer to get the render result.
        * However, on some implementation, we need a buffer with a few extra bytes for the read to
-       * happen correctly (see GLTexture::read()). So we need a custom memory allocation. */
-      /* Avoid memcpy(), replace the pointer directly. */
+       * happen correctly (see #GLTexture::read()). So we need a custom memory allocation. */
+      /* Avoid #memcpy(), replace the pointer directly. */
       RE_pass_set_buffer_data(rp, result);
       BLI_mutex_unlock(&render->update_render_passes_mutex);
     }

source/blender/draw/engines/overlay/overlay_next_shape.cc

@@ -28,7 +28,7 @@ static gpu::VertBuf *vbo_from_vector(Vector<Vertex> &vector)
   gpu::VertBuf *vbo = GPU_vertbuf_create_with_format(&format);
   GPU_vertbuf_data_alloc(vbo, vector.size());
   Vertex *vbo_data = (Vertex *)GPU_vertbuf_get_data(vbo);
-  /* Copy data to VBO using a wrapper span. Could use memcpy if that's too slow. */
+  /* Copy data to VBO using a wrapper span. Could use #memcpy if that's too slow. */
   MutableSpan<Vertex> span(vbo_data, vector.size());
   span.copy_from(vector);
   return vbo;

source/blender/editors/asset/ED_asset_shelf.hh

@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include <memory>
+
 struct ARegion;
 struct ARegionType;
 struct AssetShelf;
@@ -22,6 +24,10 @@ struct SpaceType;
 struct RegionPollParams;
 struct wmWindowManager;
 
+namespace blender {
+class StringRef;
+}  // namespace blender
+
 namespace blender::ed::asset::shelf {
 
 /* -------------------------------------------------------------------- */
@@ -64,7 +70,15 @@ void header_regiontype_register(ARegionType *region_type, const int space_type);
 /** \name Asset Shelf Type
  * \{ */
 
-bool type_poll(const bContext &C, const SpaceType &space_type, const AssetShelfType *shelf_type);
+void type_register(std::unique_ptr<AssetShelfType> type);
+void type_unregister(const AssetShelfType &shelf_type);
+/**
+ * Poll an asset shelf type for display as a permanent region in a space of a given type (the
+ * type's #bl_space_type).
+ */
+bool type_poll(const bContext &C, const AssetShelfType *shelf_type, const int space_type);
+
+AssetShelfType *type_find_from_idname(const StringRef idname);
 
 /** \} */
 

source/blender/editors/asset/intern/asset_shelf.cc

@@ -51,30 +51,70 @@ void send_redraw_notifier(const bContext &C)
 /** \name Shelf Type
  * \{ */
 
-bool type_poll(const bContext &C, const SpaceType &space_type, const AssetShelfType *shelf_type)
+static Vector<std::unique_ptr<AssetShelfType>> &static_shelf_types()
+{
+  static Vector<std::unique_ptr<AssetShelfType>> shelf_types;
+  return shelf_types;
+}
+
+void type_register(std::unique_ptr<AssetShelfType> type)
+{
+  Vector<std::unique_ptr<AssetShelfType>> &shelf_types = static_shelf_types();
+  shelf_types.append(std::move(type));
+}
+
+void type_unregister(const AssetShelfType &shelf_type)
+{
+  Vector<std::unique_ptr<AssetShelfType>> &shelf_types = static_shelf_types();
+  auto *const it = std::find_if(shelf_types.begin(),
+                                shelf_types.end(),
+                                [&](const std::unique_ptr<AssetShelfType> &iter_type) {
+                                  return iter_type.get() == &shelf_type;
+                                });
+  BLI_assert(it != shelf_types.end());
+
+  shelf_types.remove(it - shelf_types.begin());
+}
+
+bool type_poll(const bContext &C, const AssetShelfType *shelf_type, const int space_type)
 {
   if (!shelf_type) {
     return false;
   }
+  if (shelf_type->space_type && (space_type != shelf_type->space_type)) {
+    return false;
+  }
 
-  BLI_assert_msg(std::find_if(space_type.asset_shelf_types.begin(),
-                              space_type.asset_shelf_types.end(),
+#ifndef NDEBUG
+  const Vector<std::unique_ptr<AssetShelfType>> &shelf_types = static_shelf_types();
+  BLI_assert_msg(std::find_if(shelf_types.begin(),
+                              shelf_types.end(),
                               [&](const std::unique_ptr<AssetShelfType> &type) {
                                 return type.get() == shelf_type;
-                              }) != space_type.asset_shelf_types.end(),
+                              }) != shelf_types.end(),
                  "Asset shelf type is not registered");
-  UNUSED_VARS_NDEBUG(space_type);
+#endif
 
   return !shelf_type->poll || shelf_type->poll(&C, shelf_type);
 }
 
-AssetShelfType *type_ensure(const SpaceType &space_type, AssetShelf &shelf)
+AssetShelfType *type_find_from_idname(const StringRef idname)
+{
+  for (const std::unique_ptr<AssetShelfType> &shelf_type : static_shelf_types()) {
+    if (idname == shelf_type->idname) {
+      return shelf_type.get();
+    }
+  }
+  return nullptr;
+}
+
+AssetShelfType *ensure_shelf_has_type(AssetShelf &shelf)
 {
   if (shelf.type) {
     return shelf.type;
   }
 
-  for (const std::unique_ptr<AssetShelfType> &shelf_type : space_type.asset_shelf_types) {
+  for (const std::unique_ptr<AssetShelfType> &shelf_type : static_shelf_types()) {
     if (STREQ(shelf.idname, shelf_type->idname)) {
       shelf.type = shelf_type.get();
       return shelf_type.get();
@@ -138,7 +178,7 @@ static void activate_shelf(RegionAssetShelf &shelf_regiondata, AssetShelf &shelf
  *         current context (all polls failed).
  */
 static AssetShelf *update_active_shelf(const bContext &C,
-                                       const SpaceType &space_type,
+                                       const eSpace_Type space_type,
                                        RegionAssetShelf &shelf_regiondata,
                                        FunctionRef<void(AssetShelf &new_shelf)> on_create)
 {
@@ -146,7 +186,7 @@ static AssetShelf *update_active_shelf(const bContext &C,
 
   /* Case 1: */
   if (shelf_regiondata.active_shelf &&
-      type_poll(C, space_type, type_ensure(space_type, *shelf_regiondata.active_shelf)))
+      type_poll(C, ensure_shelf_has_type(*shelf_regiondata.active_shelf), space_type))
   {
     /* Not a strong precondition, but if this is wrong something weird might be going on. */
     BLI_assert(shelf_regiondata.active_shelf == shelf_regiondata.shelves.first);
@@ -160,7 +200,7 @@ static AssetShelf *update_active_shelf(const bContext &C,
       continue;
     }
 
-    if (type_poll(C, space_type, type_ensure(space_type, *shelf))) {
+    if (type_poll(C, ensure_shelf_has_type(*shelf), space_type)) {
       /* Found a valid previously activated shelf, reactivate it. */
       activate_shelf(shelf_regiondata, *shelf);
       return shelf;
@@ -168,8 +208,8 @@ static AssetShelf *update_active_shelf(const bContext &C,
   }
 
   /* Case 3: */
-  for (const std::unique_ptr<AssetShelfType> &shelf_type : space_type.asset_shelf_types) {
-    if (type_poll(C, space_type, shelf_type.get())) {
+  for (const std::unique_ptr<AssetShelfType> &shelf_type : static_shelf_types()) {
+    if (type_poll(C, shelf_type.get(), space_type)) {
       AssetShelf *new_shelf = create_shelf_from_type(*shelf_type);
       BLI_addhead(&shelf_regiondata.shelves, new_shelf);
       /* Moves ownership to the regiondata. */
@@ -216,11 +256,9 @@ void region_free(ARegion *region)
  */
 static bool asset_shelf_space_poll(const bContext *C, const SpaceLink *space_link)
 {
-  const SpaceType *space_type = BKE_spacetype_from_id(space_link->spacetype);
-
   /* Is there any asset shelf type registered that returns true for it's poll? */
-  for (const std::unique_ptr<AssetShelfType> &shelf_type : space_type->asset_shelf_types) {
-    if (type_poll(*C, *space_type, shelf_type.get())) {
+  for (const std::unique_ptr<AssetShelfType> &shelf_type : static_shelf_types()) {
+    if (type_poll(*C, shelf_type.get(), space_link->spacetype)) {
       return true;
     }
   }
@@ -251,6 +289,9 @@ static void asset_shelf_region_listen(const wmRegionListenerParams *params)
         ED_region_tag_redraw(region);
       }
       break;
+    case NC_ASSET:
+      ED_region_tag_redraw(region);
+      break;
   }
 }
 
@@ -484,7 +525,10 @@ void region_on_poll_success(const bContext *C, ARegion *region)
 
   ScrArea *area = CTX_wm_area(C);
   update_active_shelf(
-      *C, *area->type, *shelf_regiondata, /*on_create=*/[&](AssetShelf &new_shelf) {
+      *C,
+      eSpace_Type(area->spacetype),
+      *shelf_regiondata,
+      /*on_create=*/[&](AssetShelf &new_shelf) {
         /* Update region visibility (`'DEFAULT_VISIBLE'` option). */
         const int old_flag = region->flag;
         SET_FLAG_FROM_TEST(region->flag,
@@ -553,7 +597,6 @@ AssetShelf *active_shelf_from_area(const ScrArea *area)
   const ARegion *shelf_region = BKE_area_find_region_type(area, RGN_TYPE_ASSET_SHELF);
   if (!shelf_region) {
     /* Called in wrong context, area doesn't have a shelf. */
-    BLI_assert_unreachable();
     return nullptr;
   }
 
@@ -613,7 +656,7 @@ int context(const bContext *C, const char *member, bContextDataResult *result)
   /* XXX hack. Get the asset from the active item, but needs to be the file... */
   if (CTX_data_equals(member, "active_file")) {
     const ARegion *region = CTX_wm_region(C);
-    const uiBut *but = UI_region_views_find_active_item_but(region);
+    const uiBut *but = UI_region_views_find_mouse_over_but(CTX_wm_window(C), region);
     if (!but) {
       return CTX_RESULT_NO_DATA;
     }

source/blender/editors/asset/intern/asset_shelf.hh

@@ -43,7 +43,7 @@ AssetShelf *active_shelf_from_context(const bContext *C);
 
 void send_redraw_notifier(const bContext &C);
 
-AssetShelfType *type_ensure(const SpaceType &space_type, AssetShelf &shelf);
+AssetShelfType *ensure_shelf_has_type(AssetShelf &shelf);
 AssetShelf *create_shelf_from_type(AssetShelfType &type);
 
 /**

source/blender/editors/asset/intern/asset_shelf_asset_view.cc

@@ -21,6 +21,7 @@
 
 #include "ED_asset_handle.hh"
 #include "ED_asset_list.hh"
+#include "ED_asset_menu_utils.hh"
 #include "ED_asset_shelf.hh"
 
 #include "UI_grid_view.hh"
@@ -38,6 +39,7 @@ namespace blender::ed::asset::shelf {
 class AssetView : public ui::AbstractGridView {
   const AssetLibraryReference library_ref_;
   const AssetShelf &shelf_;
+  std::optional<AssetWeakReference> active_asset_;
   /** Copy of the filter string from #AssetShelfSettings, with extra '*' added to the beginning and
    * end of the string, for `fnmatch()` to work. */
   char search_string[sizeof(AssetShelfSettings::search_string) + 2] = "";
@@ -68,6 +70,7 @@ class AssetViewItem : public ui::PreviewGridItem {
   void disable_asset_drag();
   void build_grid_tile(uiLayout &layout) const override;
   void build_context_menu(bContext &C, uiLayout &column) const override;
+  std::optional<bool> should_be_active() const override;
   bool is_filtered_visible() const override;
 
   std::unique_ptr<ui::AbstractViewItemDragController> create_drag_controller() const override;
@@ -90,6 +93,14 @@ AssetView::AssetView(const AssetLibraryReference &library_ref, const AssetShelf
     BLI_strncpy_ensure_pad(
         search_string, shelf.settings.search_string, '*', sizeof(search_string));
   }
+  if (shelf.type->get_active_asset) {
+    if (const AssetWeakReference *weak_ref = shelf.type->get_active_asset(shelf.type)) {
+      active_asset_ = *weak_ref;
+    }
+    else {
+      active_asset_.reset();
+    }
+  }
 }
 
 void AssetView::build_items()
@@ -192,16 +203,17 @@ void AssetViewItem::disable_asset_drag()
 
 void AssetViewItem::build_grid_tile(uiLayout &layout) const
 {
-  PointerRNA file_ptr = RNA_pointer_create(
-      nullptr,
-      &RNA_FileSelectEntry,
-      /* XXX passing file pointer here, should be asset handle or asset representation. */
-      const_cast<FileDirEntry *>(asset_.file_data));
+  const AssetView &asset_view = reinterpret_cast<const AssetView &>(this->get_view());
+  const AssetShelfType &shelf_type = *asset_view.shelf_.type;
 
-  uiBlock *block = uiLayoutGetBlock(&layout);
-  UI_but_context_ptr_set(
-      block, reinterpret_cast<uiBut *>(view_item_but_), "active_file", &file_ptr);
-  ui::PreviewGridItem::build_grid_tile(layout);
+  wmOperatorType *ot = WM_operatortype_find(shelf_type.activate_operator.c_str(), true);
+  PointerRNA op_props = PointerRNA_NULL;
+  if (ot) {
+    WM_operator_properties_create_ptr(&op_props, ot);
+    asset::operator_asset_reference_props_set(*handle_get_representation(&asset_), op_props);
+  }
+
+  ui::PreviewGridItem::build_grid_tile_button(layout, ot, &op_props);
 }
 
 void AssetViewItem::build_context_menu(bContext &C, uiLayout &column) const
@@ -214,6 +226,19 @@ void AssetViewItem::build_context_menu(bContext &C, uiLayout &column) const
   }
 }
 
+std::optional<bool> AssetViewItem::should_be_active() const
+{
+  const AssetView &asset_view = dynamic_cast<const AssetView &>(this->get_view());
+  if (!asset_view.active_asset_) {
+    return false;
+  }
+  const asset_system::AssetRepresentation *asset = handle_get_representation(&asset_);
+  AssetWeakReference weak_ref = asset->make_weak_reference();
+  const bool matches = *asset_view.active_asset_ == weak_ref;
+
+  return matches;
+}
+
 bool AssetViewItem::is_filtered_visible() const
 {
   const AssetView &asset_view = dynamic_cast<const AssetView &>(this->get_view());

source/blender/editors/curves/intern/curves_add.cc

@@ -72,6 +72,12 @@ void ensure_surface_deformation_node_exists(bContext &C, Object &curves_ob)
   NodesModifierData &nmd = *reinterpret_cast<NodesModifierData *>(md);
   nmd.node_group = ntreeAddTree(bmain, DATA_("Surface Deform"), "GeometryNodeTree");
 
+  if (!nmd.node_group->geometry_node_asset_traits) {
+    nmd.node_group->geometry_node_asset_traits = MEM_new<GeometryNodeAssetTraits>(__func__);
+  }
+
+  nmd.node_group->geometry_node_asset_traits->flag |= GEO_NODE_ASSET_MODIFIER;
+
   bNodeTree *ntree = nmd.node_group;
   ntree->tree_interface.add_socket(
       "Geometry", "", "NodeSocketGeometry", NODE_INTERFACE_SOCKET_OUTPUT, nullptr);

source/blender/editors/geometry/node_group_operator.cc

@@ -1291,22 +1291,20 @@ void ui_template_node_operator_asset_root_items(uiLayout &layout, const bContext
     *tree = build_catalog_tree(C, *active_object);
   }
 
-  asset_system::AssetLibrary *all_library = asset::list::library_get_once_available(
-      asset_system::all_library_reference());
-  if (!all_library) {
-    return;
+  if (asset_system::AssetLibrary *all_library = asset::list::library_get_once_available(
+          asset_system::all_library_reference()))
+  {
+    const Set<std::string> builtin_menus = get_builtin_menus(ObjectType(active_object->type),
+                                                             eObjectMode(active_object->mode));
+
+    tree->catalogs.foreach_root_item([&](const asset_system::AssetCatalogTreeItem &item) {
+      if (!builtin_menus.contains_as(item.catalog_path().str())) {
+        asset::draw_menu_for_catalog(
+            screen, *all_library, item, "GEO_MT_node_operator_catalog_assets", layout);
+      }
+    });
   }
 
-  const Set<std::string> builtin_menus = get_builtin_menus(ObjectType(active_object->type),
-                                                           eObjectMode(active_object->mode));
-
-  tree->catalogs.foreach_root_item([&](const asset_system::AssetCatalogTreeItem &item) {
-    if (!builtin_menus.contains_as(item.catalog_path().str())) {
-      asset::draw_menu_for_catalog(
-          screen, *all_library, item, "GEO_MT_node_operator_catalog_assets", layout);
-    }
-  });
-
   if (!tree->unassigned_assets.is_empty() || unassigned_local_poll(C)) {
     uiItemM(&layout, "GEO_MT_node_operator_unassigned", "", ICON_FILE_HIDDEN);
   }

source/blender/editors/include/UI_grid_view.hh

@@ -19,6 +19,7 @@
 #include "UI_resources.hh"
 
 struct bContext;
+struct PointerRNA;
 struct uiBlock;
 struct uiButViewItem;
 struct uiLayout;
@@ -204,6 +205,13 @@ class PreviewGridItem : public AbstractGridViewItem {
 
   void build_grid_tile(uiLayout &layout) const override;
 
+  /**
+   * \note Takes ownership of the operator properties defined in \a op_props.
+   */
+  void build_grid_tile_button(uiLayout &layout,
+                              const wmOperatorType *ot = nullptr,
+                              const PointerRNA *op_props = nullptr) const;
+
   /**
    * Set a custom callback to execute when activating this view item. This way users don't have to
    * sub-class #PreviewGridItem, just to implement custom activation behavior (a common thing to

source/blender/editors/include/UI_interface_c.hh

@@ -3394,4 +3394,4 @@ blender::ui::AbstractView *UI_region_view_find_at(const ARegion *region, const i
 blender::ui::AbstractViewItem *UI_region_views_find_item_at(const ARegion &region,
                                                             const int xy[2]);
 blender::ui::AbstractViewItem *UI_region_views_find_active_item(const ARegion *region);
-uiBut *UI_region_views_find_active_item_but(const ARegion *region);
+uiBut *UI_region_views_find_mouse_over_but(const wmWindow *win, const ARegion *region);

source/blender/editors/interface/views/grid_view.cc

@@ -9,6 +9,7 @@
 #include <cfloat>
 #include <cmath>
 #include <limits>
+#include <optional>
 #include <stdexcept>
 
 #include "BKE_icons.h"
@@ -17,6 +18,8 @@
 
 #include "WM_types.hh"
 
+#include "RNA_access.hh"
+
 #include "UI_interface.hh"
 #include "interface_intern.hh"
 
@@ -405,23 +408,42 @@ PreviewGridItem::PreviewGridItem(StringRef identifier, StringRef label, int prev
 {
 }
 
-void PreviewGridItem::build_grid_tile(uiLayout &layout) const
+void PreviewGridItem::build_grid_tile_button(uiLayout &layout,
+                                             const wmOperatorType *ot,
+                                             const PointerRNA *op_props) const
 {
   const GridViewStyle &style = this->get_view().get_style();
   uiBlock *block = uiLayoutGetBlock(&layout);
 
-  uiBut *but = uiDefBut(block,
+  uiBut *but;
+  if (ot) {
+    but = uiDefButO_ptr(block,
                         UI_BTYPE_PREVIEW_TILE,
-                        0,
+                        const_cast<wmOperatorType *>(ot),
+                        WM_OP_INVOKE_REGION_WIN,
                         hide_label_ ? "" : label,
                         0,
                         0,
                         style.tile_width,
                         style.tile_height,
-                        nullptr,
-                        0,
-                        0,
                         "");
+    but->opptr = MEM_new<PointerRNA>(__func__, *op_props);
+  }
+  else {
+    but = uiDefBut(block,
+                   UI_BTYPE_PREVIEW_TILE,
+                   0,
+                   hide_label_ ? "" : label,
+                   0,
+                   0,
+                   style.tile_width,
+                   style.tile_height,
+                   nullptr,
+                   0,
+                   0,
+                   "");
+  }
+
   /* Draw icons that are not previews or images as normal icons with a fixed icon size. Otherwise
    * they will be upscaled to the button size. Should probably be done by the widget code. */
   const int is_preview_flag = (BKE_icon_is_preview(preview_icon_id) ||
@@ -436,6 +458,11 @@ void PreviewGridItem::build_grid_tile(uiLayout &layout) const
   but->emboss = UI_EMBOSS_NONE;
 }
 
+void PreviewGridItem::build_grid_tile(uiLayout &layout) const
+{
+  this->build_grid_tile_button(layout);
+}
+
 void PreviewGridItem::set_on_activate_fn(ActivateFn fn)
 {
   activate_fn_ = fn;

source/blender/editors/interface/views/interface_view.cc

@@ -201,9 +201,9 @@ ui::AbstractViewItem *UI_region_views_find_active_item(const ARegion *region)
   return item_but->view_item;
 }
 
-uiBut *UI_region_views_find_active_item_but(const ARegion *region)
+uiBut *UI_region_views_find_mouse_over_but(const wmWindow *win, const ARegion *region)
 {
-  return ui_view_item_find_active(region);
+  return ui_view_item_find_mouse_over(region, win->eventstate->xy);
 }
 
 namespace blender::ui {

source/blender/editors/io/io_alembic.cc

@@ -697,11 +697,13 @@ void WM_OT_alembic_import(wmOperatorType *ot)
       "Set Frame Range",
       "If checked, update scene's start and end frame to match those of the Alembic archive");
 
-  RNA_def_boolean(ot->srna,
-                  "validate_meshes",
-                  false,
-                  "Validate Meshes",
-                  "Check imported mesh objects for invalid data (slow)");
+  RNA_def_boolean(
+      ot->srna,
+      "validate_meshes",
+      false,
+      "Validate Meshes",
+      "Ensure the data is valid "
+      "(when disabled, data may be imported which causes crashes displaying or editing)");
 
   RNA_def_boolean(ot->srna,
                   "always_add_cache_reader",

source/blender/editors/io/io_obj.cc

@@ -392,7 +392,7 @@ void WM_OT_obj_export(wmOperatorType *ot)
   RNA_def_boolean(
       ot->srna, "smooth_group_bitflags", false, "Generate Bitflags for Smooth Groups", "");
 
-  /* Only show .obj or .mtl files by default. */
+  /* Only show `.obj` or `.mtl` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.obj;*.mtl", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 
@@ -537,11 +537,13 @@ void WM_OT_obj_import(wmOperatorType *ot)
                   false,
                   "Vertex Groups",
                   "Import OBJ groups as vertex groups");
-  RNA_def_boolean(ot->srna,
-                  "validate_meshes",
-                  false,
-                  "Validate Meshes",
-                  "Check imported mesh objects for invalid data (slow)");
+  RNA_def_boolean(
+      ot->srna,
+      "validate_meshes",
+      true,
+      "Validate Meshes",
+      "Ensure the data is valid "
+      "(when disabled, data may be imported which causes crashes displaying or editing)");
 
   RNA_def_string(ot->srna,
                  "collection_separator",
@@ -550,7 +552,7 @@ void WM_OT_obj_import(wmOperatorType *ot)
                  "Path Separator",
                  "Character used to separate objects name into hierarchical structure");
 
-  /* Only show .obj or .mtl files by default. */
+  /* Only show `.obj` or `.mtl` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.obj;*.mtl", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }

source/blender/editors/io/io_ply_ops.cc

@@ -238,7 +238,7 @@ void WM_OT_ply_export(wmOperatorType *ot)
                   "ASCII Format",
                   "Export file in ASCII format, export as binary otherwise");
 
-  /* Only show .ply files by default. */
+  /* Only show `.ply` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.ply", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }
@@ -339,7 +339,7 @@ void WM_OT_ply_import(wmOperatorType *ot)
   RNA_def_boolean(
       ot->srna, "import_attributes", true, "Vertex Attributes", "Import custom vertex attributes");
 
-  /* Only show .ply files by default. */
+  /* Only show `.ply` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.ply", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }

source/blender/editors/io/io_stl_ops.cc

@@ -184,7 +184,7 @@ void WM_OT_stl_export(wmOperatorType *ot)
   RNA_def_boolean(
       ot->srna, "apply_modifiers", true, "Apply Modifiers", "Apply modifiers to exported meshes");
 
-  /* Only show .stl files by default. */
+  /* Only show `.stl` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.stl", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }
@@ -291,13 +291,16 @@ void WM_OT_stl_import(wmOperatorType *ot)
                   "Use (import) facet normals (note that this will still give flat shading)");
   RNA_def_enum(ot->srna, "forward_axis", io_transform_axis, IO_AXIS_Y, "Forward Axis", "");
   RNA_def_enum(ot->srna, "up_axis", io_transform_axis, IO_AXIS_Z, "Up Axis", "");
-  RNA_def_boolean(ot->srna,
-                  "use_mesh_validate",
-                  false,
-                  "Validate Mesh",
-                  "Validate and correct imported mesh (slow)");
 
-  /* Only show .stl files by default. */
+  RNA_def_boolean(
+      ot->srna,
+      "use_mesh_validate",
+      true,
+      "Validate Mesh",
+      "Ensure the data is valid "
+      "(when disabled, data may be imported which causes crashes displaying or editing)");
+
+  /* Only show `.stl` files by default. */
   prop = RNA_def_string(ot->srna, "filter_glob", "*.stl", 0, "Extension Filter", "");
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }

source/blender/editors/io/io_usd.cc

@@ -884,11 +884,13 @@ void WM_OT_usd_import(wmOperatorType *ot)
                "Custom Properties",
                "Behavior when importing USD attributes as Blender custom properties");
 
-  RNA_def_boolean(ot->srna,
-                  "validate_meshes",
-                  false,
-                  "Validate Meshes",
-                  "Check imported mesh objects for invalid data (slow)");
+  RNA_def_boolean(
+      ot->srna,
+      "validate_meshes",
+      false,
+      "Validate Meshes",
+      "Ensure the data is valid "
+      "(when disabled, data may be imported which causes crashes displaying or editing)");
 }
 
 namespace blender::ed::io {

source/blender/editors/sculpt_paint/grease_pencil_paint.cc

@@ -137,7 +137,7 @@ class PaintOperation : public GreasePencilStrokeOperation {
   void on_stroke_done(const bContext &C) override;
 
  private:
-  void simplify_stroke(bke::greasepencil::Drawing &drawing, float epsilon_px);
+  void simplify_stroke(const bContext &C, bke::greasepencil::Drawing &drawing, float epsilon_px);
   void process_stroke_end(const bContext &C, bke::greasepencil::Drawing &drawing);
 };
 
@@ -190,6 +190,100 @@ struct PaintOperationExecutor {
     BLI_assert(drawing_ != nullptr);
   }
 
+  /**
+   * Creates a new curve with one point at the beginning or end.
+   * Note: Does not initialize the new curve or points.
+   */
+  static void create_blank_curve(bke::CurvesGeometry &curves, const bool on_back)
+  {
+    if (!on_back) {
+      const int num_old_points = curves.points_num();
+      curves.resize(curves.points_num() + 1, curves.curves_num() + 1);
+      curves.offsets_for_write().last(1) = num_old_points;
+      return;
+    }
+
+    curves.resize(curves.points_num() + 1, curves.curves_num() + 1);
+    MutableSpan<int> offsets = curves.offsets_for_write();
+    offsets.first() = 0;
+
+    /* Loop through backwards to not overwrite the data. */
+    for (int i = curves.curves_num() - 2; i >= 0; i--) {
+      offsets[i + 1] = offsets[i] + 1;
+    }
+
+    bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+
+    attributes.for_all(
+        [&](const bke::AttributeIDRef &id, const bke::AttributeMetaData /*meta_data*/) {
+          bke::GSpanAttributeWriter dst = attributes.lookup_for_write_span(id);
+
+          GMutableSpan attribute_data = dst.span;
+
+          bke::attribute_math::convert_to_static_type(attribute_data.type(), [&](auto dummy) {
+            using T = decltype(dummy);
+            MutableSpan<T> span_data = attribute_data.typed<T>();
+
+            /* Loop through backwards to not overwrite the data. */
+            for (int i = span_data.size() - 2; i >= 0; i--) {
+              span_data[i + 1] = span_data[i];
+            }
+          });
+          dst.finish();
+          return true;
+        });
+  }
+
+  /**
+   * Extends the first or last curve by `new_points_num` number of points.
+   * Note: Does not initialize the new points.
+   */
+  static void extend_curve(bke::CurvesGeometry &curves,
+                           const bool on_back,
+                           const int new_points_num)
+  {
+    if (!on_back) {
+      curves.resize(curves.points_num() + new_points_num, curves.curves_num());
+      curves.offsets_for_write().last() = curves.points_num();
+      return;
+    }
+
+    const int last_active_point = curves.points_by_curve()[0].last();
+
+    curves.resize(curves.points_num() + new_points_num, curves.curves_num());
+    MutableSpan<int> offsets = curves.offsets_for_write();
+
+    for (const int src_curve : curves.curves_range().drop_front(1)) {
+      offsets[src_curve] = offsets[src_curve] + new_points_num;
+    }
+    offsets.last() = curves.points_num();
+
+    bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+
+    attributes.for_all([&](const bke::AttributeIDRef &id, const bke::AttributeMetaData meta_data) {
+      if (meta_data.domain != bke::AttrDomain::Point) {
+        return true;
+      }
+
+      bke::GSpanAttributeWriter dst = attributes.lookup_for_write_span(id);
+      GMutableSpan attribute_data = dst.span;
+
+      bke::attribute_math::convert_to_static_type(attribute_data.type(), [&](auto dummy) {
+        using T = decltype(dummy);
+        MutableSpan<T> span_data = attribute_data.typed<T>();
+
+        /* Loop through backwards to not overwrite the data. */
+        for (int i = (span_data.size() - 1) - new_points_num; i >= last_active_point; i--) {
+          span_data[i + new_points_num] = span_data[i];
+        }
+      });
+      dst.finish();
+      return true;
+    });
+
+    curves.tag_topology_changed();
+  }
+
   /* Attributes that are defined explicitly and should not be copied from original geometry. */
   Set<std::string> skipped_attribute_ids(const bke::AttrDomain domain) const
   {
@@ -237,6 +331,8 @@ struct PaintOperationExecutor {
         settings_);
     const float start_opacity = ed::greasepencil::opacity_from_input_sample(
         start_sample.pressure, brush_, scene_, settings_);
+    Scene *scene = CTX_data_scene(&C);
+    const bool on_back = (scene->toolsettings->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK) != 0;
 
     self.screen_space_coords_orig_.append(start_coords);
     self.screen_space_curve_fitted_coords_.append(Vector<float2>({start_coords}));
@@ -244,18 +340,21 @@ struct PaintOperationExecutor {
 
     /* Resize the curves geometry so there is one more curve with a single point. */
     bke::CurvesGeometry &curves = drawing_->strokes_for_write();
-    const int num_old_points = curves.points_num();
-    curves.resize(curves.points_num() + 1, curves.curves_num() + 1);
-    curves.offsets_for_write().last(1) = num_old_points;
+    create_blank_curve(curves, on_back);
 
-    curves.positions_for_write().last() = self.placement_.project(start_coords);
-    drawing_->radii_for_write().last() = start_radius;
-    drawing_->opacities_for_write().last() = start_opacity;
+    const int active_curve = on_back ? curves.curves_range().first() :
+                                       curves.curves_range().last();
+    const IndexRange curve_points = curves.points_by_curve()[active_curve];
+    const int last_active_point = curve_points.last();
+
+    curves.positions_for_write()[last_active_point] = self.placement_.project(start_coords);
+    drawing_->radii_for_write()[last_active_point] = start_radius;
+    drawing_->opacities_for_write()[last_active_point] = start_opacity;
     if (vertex_color_) {
-      drawing_->vertex_colors_for_write().last() = *vertex_color_;
+      drawing_->vertex_colors_for_write()[last_active_point] = *vertex_color_;
     }
     if (fill_color_) {
-      drawing_->fill_colors_for_write().last() = *fill_color_;
+      drawing_->fill_colors_for_write()[active_curve] = *fill_color_;
     }
 
     bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
@@ -267,22 +366,22 @@ struct PaintOperationExecutor {
         "hardness",
         bke::AttrDomain::Curve,
         bke::AttributeInitVArray(VArray<float>::ForSingle(1.0f, curves.curves_num())));
-    cyclic.span.last() = false;
-    materials.span.last() = material_index;
-    hardnesses.span.last() = hardness_;
+    cyclic.span[active_curve] = false;
+    materials.span[active_curve] = material_index;
+    hardnesses.span[active_curve] = hardness_;
 
     /* Only set the attribute if the type is not the default or if it already exists. */
     if (settings_->caps_type != GP_STROKE_CAP_TYPE_ROUND || attributes.contains("start_cap")) {
       bke::SpanAttributeWriter<int8_t> start_caps =
           attributes.lookup_or_add_for_write_span<int8_t>("start_cap", bke::AttrDomain::Curve);
-      start_caps.span.last() = settings_->caps_type;
+      start_caps.span[active_curve] = settings_->caps_type;
       start_caps.finish();
     }
 
     if (settings_->caps_type != GP_STROKE_CAP_TYPE_ROUND || attributes.contains("end_cap")) {
       bke::SpanAttributeWriter<int8_t> end_caps = attributes.lookup_or_add_for_write_span<int8_t>(
           "end_cap", bke::AttrDomain::Curve);
-      end_caps.span.last() = settings_->caps_type;
+      end_caps.span[active_curve] = settings_->caps_type;
       end_caps.finish();
     }
 
@@ -290,18 +389,18 @@ struct PaintOperationExecutor {
     materials.finish();
     hardnesses.finish();
 
-    curves.curve_types_for_write().last() = CURVE_TYPE_POLY;
+    curves.curve_types_for_write()[active_curve] = CURVE_TYPE_POLY;
     curves.update_curve_types();
 
     /* Initialize the rest of the attributes with default values. */
     bke::fill_attribute_range_default(attributes,
                                       bke::AttrDomain::Point,
                                       this->skipped_attribute_ids(bke::AttrDomain::Point),
-                                      curves.points_range().take_back(1));
+                                      IndexRange(last_active_point, 1));
     bke::fill_attribute_range_default(attributes,
                                       bke::AttrDomain::Curve,
                                       this->skipped_attribute_ids(bke::AttrDomain::Curve),
-                                      curves.curves_range().take_back(1));
+                                      IndexRange(active_curve, 1));
 
     drawing_->tag_topology_changed();
   }
@@ -405,14 +504,21 @@ struct PaintOperationExecutor {
         settings_);
     const float opacity = ed::greasepencil::opacity_from_input_sample(
         extension_sample.pressure, brush_, scene_, settings_);
+    Scene *scene = CTX_data_scene(&C);
+    const bool on_back = (scene->toolsettings->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK) != 0;
 
     bke::CurvesGeometry &curves = drawing_->strokes_for_write();
     bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
 
+    const int active_curve = on_back ? curves.curves_range().first() :
+                                       curves.curves_range().last();
+    const IndexRange curve_points = curves.points_by_curve()[active_curve];
+    const int last_active_point = curve_points.last();
+
     const float2 prev_coords = self.screen_space_coords_orig_.last();
-    const float prev_radius = drawing_->radii().last();
-    const float prev_opacity = drawing_->opacities().last();
-    const ColorGeometry4f prev_vertex_color = drawing_->vertex_colors().last();
+    const float prev_radius = drawing_->radii()[last_active_point];
+    const float prev_opacity = drawing_->opacities()[last_active_point];
+    const ColorGeometry4f prev_vertex_color = drawing_->vertex_colors()[last_active_point];
 
     /* Overwrite last point if it's very close. */
     const IndexRange points_range = curves.points_by_curve()[curves.curves_range().last()];
@@ -420,10 +526,10 @@ struct PaintOperationExecutor {
     if (math::distance(coords, prev_coords) < POINT_OVERRIDE_THRESHOLD_PX) {
       /* Don't move the first point of the stroke. */
       if (!is_first_sample) {
-        curves.positions_for_write().last() = self.placement_.project(coords);
+        curves.positions_for_write()[last_active_point] = self.placement_.project(coords);
       }
-      drawing_->radii_for_write().last() = math::max(radius, prev_radius);
-      drawing_->opacities_for_write().last() = math::max(opacity, prev_opacity);
+      drawing_->radii_for_write()[last_active_point] = math::max(radius, prev_radius);
+      drawing_->opacities_for_write()[last_active_point] = math::max(opacity, prev_opacity);
       return;
     }
 
@@ -436,12 +542,9 @@ struct PaintOperationExecutor {
     }
 
     /* Resize the curves geometry. */
-    curves.resize(curves.points_num() + new_points_num, curves.curves_num());
-    curves.offsets_for_write().last() = curves.points_num();
-    const IndexRange curve_points = curves.points_by_curve()[curves.curves_range().last()];
-
+    extend_curve(curves, on_back, new_points_num);
     /* Subdivide stroke in new_points. */
-    const IndexRange new_points = curve_points.take_back(new_points_num);
+    const IndexRange new_points = curves.points_by_curve()[active_curve].take_back(new_points_num);
     Array<float2> new_screen_space_coords(new_points_num);
     MutableSpan<float3> positions = curves.positions_for_write();
     MutableSpan<float3> new_positions = positions.slice(new_points);
@@ -473,7 +576,8 @@ struct PaintOperationExecutor {
     }
     else {
       /* Active smoothing is done in a window at the end of the new stroke. */
-      this->active_smoothing(self, smooth_window, positions.slice(curve_points));
+      this->active_smoothing(
+          self, smooth_window, positions.slice(curves.points_by_curve()[active_curve]));
     }
 
     /* Initialize the rest of the attributes with default values. */
@@ -483,7 +587,7 @@ struct PaintOperationExecutor {
                                       curves.points_range().take_back(1));
 
     drawing_->set_texture_matrices(Span<float4x2>(&(self.texture_space_), 1),
-                                   IndexMask(IndexRange(curves.curves_range().last(), 1)));
+                                   IndexMask(IndexRange(active_curve, 1)));
   }
 
   void execute(PaintOperation &self, const bContext &C, const InputSample &extension_sample)
@@ -609,10 +713,15 @@ static float dist_to_interpolated_2d(
   return 0.0f;
 }
 
-void PaintOperation::simplify_stroke(bke::greasepencil::Drawing &drawing, const float epsilon_px)
+void PaintOperation::simplify_stroke(const bContext &C,
+                                     bke::greasepencil::Drawing &drawing,
+                                     const float epsilon_px)
 {
-  const int stroke_index = drawing.strokes().curves_range().last();
-  const IndexRange points = drawing.strokes().points_by_curve()[stroke_index];
+  const Scene *scene = CTX_data_scene(&C);
+  const bool on_back = (scene->toolsettings->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK) != 0;
+  const int active_curve = on_back ? drawing.strokes().curves_range().first() :
+                                     drawing.strokes().curves_range().last();
+  const IndexRange points = drawing.strokes().points_by_curve()[active_curve];
   bke::CurvesGeometry &curves = drawing.strokes_for_write();
   const VArray<float> radii = drawing.radii();
 
@@ -643,11 +752,60 @@ void PaintOperation::simplify_stroke(bke::greasepencil::Drawing &drawing, const
   }
 }
 
+static void remove_points_from_end_of_active_curve(bke::CurvesGeometry &curves,
+                                                   const bool on_back,
+                                                   const int rem_points_num)
+{
+  if (!on_back) {
+    curves.resize(curves.points_num() - rem_points_num, curves.curves_num());
+    curves.offsets_for_write().last() = curves.points_num();
+    return;
+  }
+
+  bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+  const int last_active_point = curves.points_by_curve()[0].last();
+
+  /* Shift the data before resizing to not delete the data at the end. */
+  attributes.for_all([&](const bke::AttributeIDRef &id, const bke::AttributeMetaData meta_data) {
+    if (meta_data.domain != bke::AttrDomain::Point) {
+      return true;
+    }
+
+    bke::GSpanAttributeWriter dst = attributes.lookup_for_write_span(id);
+    GMutableSpan attribute_data = dst.span;
+
+    bke::attribute_math::convert_to_static_type(attribute_data.type(), [&](auto dummy) {
+      using T = decltype(dummy);
+      MutableSpan<T> span_data = attribute_data.typed<T>();
+
+      for (int i = last_active_point - rem_points_num + 1;
+           i < curves.points_num() - rem_points_num;
+           i++)
+      {
+        span_data[i] = span_data[i + rem_points_num];
+      }
+    });
+    dst.finish();
+    return true;
+  });
+
+  curves.resize(curves.points_num() - rem_points_num, curves.curves_num());
+  MutableSpan<int> offsets = curves.offsets_for_write();
+  for (const int src_curve : curves.curves_range().drop_front(1)) {
+    offsets[src_curve] = offsets[src_curve] - rem_points_num;
+  }
+  offsets.last() = curves.points_num();
+
+  curves.tag_topology_changed();
+}
+
 void PaintOperation::process_stroke_end(const bContext &C, bke::greasepencil::Drawing &drawing)
 {
   Scene *scene = CTX_data_scene(&C);
-  const int stroke_index = drawing.strokes().curves_range().last();
-  IndexRange points = drawing.strokes().points_by_curve()[stroke_index];
+  const bool on_back = (scene->toolsettings->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK) != 0;
+  const int active_curve = on_back ? drawing.strokes().curves_range().first() :
+                                     drawing.strokes().curves_range().last();
+  IndexRange points = drawing.strokes().points_by_curve()[active_curve];
   bke::CurvesGeometry &curves = drawing.strokes_for_write();
   const VArray<float> radii = drawing.radii();
 
@@ -662,8 +820,7 @@ void PaintOperation::process_stroke_end(const bContext &C, bke::greasepencil::Dr
     }
   }
   if (points_to_remove > 0) {
-    curves.resize(curves.points_num() - points_to_remove, curves.curves_num());
-    curves.offsets_for_write().last() = curves.points_num();
+    remove_points_from_end_of_active_curve(curves, on_back, points_to_remove);
     points = points.drop_back(points_to_remove);
   }
 
@@ -674,7 +831,7 @@ void PaintOperation::process_stroke_end(const bContext &C, bke::greasepencil::Dr
       curves, selection_domain, CD_PROP_BOOL);
 
   if (selection_domain == bke::AttrDomain::Curve) {
-    ed::curves::fill_selection_false(selection.span.slice(IndexRange(stroke_index, 1)));
+    ed::curves::fill_selection_false(selection.span.slice(IndexRange(active_curve, 1)));
   }
   else if (selection_domain == bke::AttrDomain::Point) {
     ed::curves::fill_selection_false(selection.span.slice(points));
@@ -704,7 +861,7 @@ void PaintOperation::on_stroke_done(const bContext &C)
       reinterpret_cast<GreasePencilDrawing *>(grease_pencil.drawing(drawing_index))->wrap();
 
   const float simplifiy_threshold_px = 0.5f;
-  this->simplify_stroke(drawing, simplifiy_threshold_px);
+  this->simplify_stroke(C, drawing, simplifiy_threshold_px);
   this->process_stroke_end(C, drawing);
   drawing.tag_topology_changed();
 

source/blender/editors/space_sequencer/sequencer_edit.cc

@@ -2979,7 +2979,7 @@ static int sequencer_export_subtitles_exec(bContext *C, wmOperator *op)
   Sequence *seq, *seq_next;
   Editing *ed = SEQ_editing_get(scene);
   ListBase text_seq = {nullptr};
-  int iter = 1; /* Sequence numbers in .srt files are 1-indexed. */
+  int iter = 1; /* Sequence numbers in `.srt` files are 1-indexed. */
   FILE *file;
   char filepath[FILE_MAX];
 

source/blender/freestyle/intern/stroke/BasicStrokeShaders.h

@@ -68,7 +68,7 @@ class ConstantThicknessShader : public StrokeShader {
 /* [ Thickness Shader ].
  *  Assigns an absolute constant external thickness to every vertices of the Stroke. The external
  * thickness of a point is its thickness from the point to the strip border in the direction
- * pointing outside the object the Stroke delimitates.
+ * pointing outside the object the Stroke delimiters.
  */
 class ConstantExternThicknessShader : public StrokeShader {
  public:

source/blender/gpu/metal/mtl_backend.hh

@@ -56,8 +56,8 @@ class MTLBackend : public GPUBackend {
   void compute_dispatch(int groups_x_len, int groups_y_len, int groups_z_len) override;
   void compute_dispatch_indirect(StorageBuf *indirect_buf) override;
 
-  /* MTL Allocators need to be implemented in separate .mm files, due to allocation of Objective-C
-   * objects. */
+  /* MTL Allocators need to be implemented in separate `.mm` files,
+   * due to allocation of Objective-C objects. */
   Context *context_alloc(void *ghost_window, void *ghost_context) override;
   Batch *batch_alloc() override;
   DrawList *drawlist_alloc(int list_length) override;

source/blender/io/ply/IO_ply.hh

@@ -24,7 +24,7 @@ enum ePLYVertexColorMode {
 };
 
 struct PLYExportParams {
-  /** Full path to the destination .PLY file. */
+  /** Full path to the destination `.PLY` file. */
   char filepath[FILE_MAX];
   /** Pretend that destination file folder is this, if non-empty. Used only for tests. */
   char file_base_for_tests[FILE_MAX];

source/blender/io/ply/importer/ply_import_mesh.cc

@@ -99,16 +99,14 @@ Mesh *convert_ply_to_mesh(PlyData &data, const PLYImportParams &params)
     uv_map.finish();
   }
 
-  /* Calculate edges from the rest of the mesh. */
-  bke::mesh_calc_edges(*mesh, true, false);
-
   /* If we have custom vertex normals, set them (note: important to do this
    * after initializing the loops). */
+  bool set_custom_normals_for_verts = false;
   if (!data.vertex_normals.is_empty()) {
     if (!data.face_sizes.is_empty()) {
       /* For a non-point-cloud mesh, set custom normals. */
-      BKE_mesh_set_custom_normals_from_verts(
-          mesh, reinterpret_cast<float(*)[3]>(data.vertex_normals.data()));
+      /* Deferred because this relies on valid mesh data. */
+      set_custom_normals_for_verts = true;
     }
     else if (params.import_attributes) {
       /* If we have no faces, add vertex normals as custom attribute. */
@@ -132,6 +130,23 @@ Mesh *convert_ply_to_mesh(PlyData &data, const PLYImportParams &params)
     }
   }
 
+  /* It's important to validate the mesh before using it's geometry to calculate derived data. */
+  {
+    /* Calculate edges from the rest of the mesh (this could be merged with validate). */
+    bke::mesh_calc_edges(*mesh, true, false);
+
+    bool verbose_validate = false;
+#ifndef NDEBUG
+    verbose_validate = true;
+#endif
+    BKE_mesh_validate(mesh, verbose_validate, false);
+  }
+
+  if (set_custom_normals_for_verts) {
+    BKE_mesh_set_custom_normals_from_verts(
+        mesh, reinterpret_cast<float(*)[3]>(data.vertex_normals.data()));
+  }
+
   /* Merge all vertices on the same location. */
   if (params.merge_verts) {
     std::optional<Mesh *> merged_mesh = blender::geometry::mesh_merge_by_distance_all(

source/blender/io/stl/exporter/stl_export.cc

@@ -85,7 +85,7 @@ void export_frame(Depsgraph *depsgraph,
       char filepath[FILE_MAX];
       STRNCPY(filepath, export_params.filepath);
       BLI_path_suffix(filepath, FILE_MAX, object_name, "");
-      /* Make sure we have .stl extension (case insensitive). */
+      /* Make sure we have `.stl` extension (case insensitive). */
       if (!BLI_path_extension_check(filepath, ".stl")) {
         BLI_path_extension_ensure(filepath, FILE_MAX, ".stl");
       }

source/blender/io/usd/intern/usd_capi_export.cc

@@ -426,9 +426,11 @@ static void export_endjob(void *customdata)
   report_job_duration(data);
 }
 
-/* To create a usdz file, we must first create a .usd/a/c file and then covert it to .usdz. The
- * temporary files will be created in Blender's temporary session storage. The .usdz file will then
- * be moved to job->usdz_filepath. */
+/**
+ * To create a USDZ file, we must first create a `.usd/a/c` file and then covert it to `.usdz`.
+ * The temporary files will be created in Blender's temporary session storage.
+ * The `.usdz` file will then be moved to `job->usdz_filepath`.
+ */
 static void create_temp_path_for_usdz_export(const char *filepath,
                                              blender::io::usd::ExportJobData *job)
 {

source/blender/io/usd/intern/usd_writer_volume.cc

@@ -95,8 +95,8 @@ std::optional<std::string> USDVolumeWriter::resolve_vdb_file(const Volume *volum
   std::optional<std::string> vdb_file_path;
   if (volume->filepath[0] == '\0') {
     /* Entering this section should mean that Volume object contains OpenVDB data that is not
-     * obtained from external .vdb file but rather generated inside of Blender (i.e. by 'Mesh to
-     * Volume' modifier). Try to save this data to a .vdb file. */
+     * obtained from external `.vdb` file but rather generated inside of Blender (i.e. by 'Mesh to
+     * Volume' modifier). Try to save this data to a `.vdb` file. */
 
     vdb_file_path = construct_vdb_file_path(volume);
     if (!BKE_volume_save(

source/blender/io/usd/intern/usd_writer_volume.hh

@@ -11,8 +11,8 @@ struct Volume;
 
 namespace blender::io::usd {
 
-/* Writer for writing OpenVDB assets to UsdVolVolume. Volume data is stored in separate .vdb files
- * which are referenced in USD file. */
+/* Writer for writing OpenVDB assets to UsdVolVolume. Volume data is stored in separate `.vdb`
+ * files which are referenced in USD file. */
 class USDVolumeWriter : public USDAbstractWriter {
  public:
   USDVolumeWriter(const USDExporterContext &ctx);
@@ -22,11 +22,11 @@ class USDVolumeWriter : public USDAbstractWriter {
   virtual void do_write(HierarchyContext &context) override;
 
  private:
-  /* Try to ensure that external .vdb file is available for USD to be referenced. Blender can
+  /* Try to ensure that external `.vdb` file is available for USD to be referenced. Blender can
    * either reference external OpenVDB data or generate such data internally. Latter option will
-   * mean that `resolve_vdb_file` method will try to export volume data to a new .vdb file. If
-   * successful, this method returns absolute file path to the resolved .vdb file, if not, returns
-   * `std::nullopt`. */
+   * mean that `resolve_vdb_file` method will try to export volume data to a new `.vdb` file.
+   * If successful, this method returns absolute file path to the resolved `.vdb` file, if not,
+   * returns `std::nullopt`. */
   std::optional<std::string> resolve_vdb_file(const Volume *volume) const;
 
   std::optional<std::string> construct_vdb_file_path(const Volume *volume) const;

source/blender/io/wavefront_obj/IO_wavefront_obj.hh

@@ -19,7 +19,7 @@ struct bContext;
 struct ReportList;
 
 struct OBJExportParams {
-  /** Full path to the destination .OBJ file. */
+  /** Full path to the destination `.OBJ` file. */
   char filepath[FILE_MAX];
   /** Pretend that destination file folder is this, if non-empty. Used only for tests. */
   char file_base_for_tests[FILE_MAX];
@@ -77,7 +77,7 @@ struct OBJImportParams {
   bool use_split_objects = true;
   bool use_split_groups = false;
   bool import_vertex_groups = false;
-  bool validate_meshes = false;
+  bool validate_meshes = true;
   bool relative_paths = true;
   bool clear_selection = true;
 

source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc

@@ -173,7 +173,7 @@ void OBJWriter::write_header() const
 
 void OBJWriter::write_mtllib_name(const StringRefNull mtl_filepath) const
 {
-  /* Split .MTL file path into parent directory and filename. */
+  /* Split `.MTL` file path into parent directory and filename. */
   char mtl_file_name[FILE_MAXFILE];
   char mtl_dir_name[FILE_MAXDIR];
   BLI_path_split_dir_file(mtl_filepath.data(),
@@ -497,7 +497,7 @@ void OBJWriter::write_nurbs_curve(FormatHandler &fh, const OBJCurve &obj_nurbs_d
 }
 
 /* -------------------------------------------------------------------- */
-/** \name .MTL writers.
+/** \name `.MTL` writers.
  * \{ */
 
 static const char *tex_map_type_to_string[] = {

source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh

@@ -33,7 +33,7 @@ struct IndexOffsets {
 };
 
 /**
- * Responsible for writing a .OBJ file.
+ * Responsible for writing a `.OBJ` file.
  */
 class OBJWriter : NonMovable, NonCopyable {
  private:
@@ -70,7 +70,7 @@ class OBJWriter : NonMovable, NonCopyable {
    */
   void write_object_name(FormatHandler &fh, const OBJMesh &obj_mesh_data) const;
   /**
-   * Write file name of Material Library in .OBJ file.
+   * Write file name of Material Library in `.OBJ` file.
    */
   void write_mtllib_name(const StringRefNull mtl_filepath) const;
   /**
@@ -93,7 +93,7 @@ class OBJWriter : NonMovable, NonCopyable {
    * Write face elements with at least vertex indices, and conditionally with UV vertex
    * indices and face normal indices. Also write groups: smooth, vertex, material.
    * The matname_fn turns a 0-indexed material slot number in an Object into the
-   * name used in the .obj file.
+   * name used in the `.obj` file.
    * \note UV indices were stored while writing UV vertices.
    */
   void write_face_elements(FormatHandler &fh,
@@ -107,7 +107,7 @@ class OBJWriter : NonMovable, NonCopyable {
                            const IndexOffsets &offsets,
                            const OBJMesh &obj_mesh_data) const;
   /**
-   * Write a NURBS curve to the .OBJ file in parameter form.
+   * Write a NURBS curve to the `.OBJ` file in parameter form.
    */
   void write_nurbs_curve(FormatHandler &fh, const OBJCurve &obj_nurbs_data) const;
 
@@ -162,7 +162,7 @@ class OBJWriter : NonMovable, NonCopyable {
 };
 
 /**
- * Responsible for writing a .MTL file.
+ * Responsible for writing a `.MTL` file.
  */
 class MTLWriter : NonMovable, NonCopyable {
  private:
@@ -175,7 +175,7 @@ class MTLWriter : NonMovable, NonCopyable {
 
  public:
   /*
-   * Create the .MTL file.
+   * Create the `.MTL` file.
    */
   MTLWriter(const char *obj_filepath) noexcept(false);
   ~MTLWriter();

source/blender/io/wavefront_obj/exporter/obj_export_mtl.cc

@@ -142,7 +142,7 @@ static std::string get_image_filepath(const bNode *tex_node)
   }
 
   if (BKE_image_has_packedfile(tex_image)) {
-    /* Put image in the same directory as the .MTL file. */
+    /* Put image in the same directory as the `.MTL` file. */
     const char *filename = BLI_path_basename(tex_image->filepath);
     fprintf(stderr,
             "Packed image found:'%s'. Unpack and place the image in the same "

source/blender/io/wavefront_obj/exporter/obj_export_mtl.hh

@@ -46,7 +46,7 @@ struct MTLTexMap {
 };
 
 /**
- * Container suited for storing Material data for/from a .MTL file.
+ * Container suited for storing Material data for/from an `.MTL` file.
  */
 struct MTLMaterial {
   const MTLTexMap &tex_map_of_type(MTLTexMapType key) const

source/blender/io/wavefront_obj/exporter/obj_exporter.cc

@@ -225,7 +225,7 @@ static void write_mesh_objects(const Span<std::unique_ptr<OBJMesh>> exportable_a
           obj_writer.write_uv_coords(fh, obj);
         }
         /* This function takes a 0-indexed slot index for the obj_mesh object and
-         * returns the material name that we are using in the .obj file for it. */
+         * returns the material name that we are using in the `.obj` file for it. */
         const auto *obj_mtlindices = mtlindices.is_empty() ? nullptr : &mtlindices[i];
         auto matname_fn = [&](int s) -> const char * {
           if (!obj_mtlindices || s < 0 || s >= obj_mtlindices->size()) {
@@ -319,7 +319,9 @@ void export_frame(Depsgraph *depsgraph, const OBJExportParams &export_params, co
   write_nurbs_curve_objects(exportable_as_nurbs, *frame_writer);
 }
 
-bool append_frame_to_filename(const char *filepath, const int frame, char *r_filepath_with_frames)
+bool append_frame_to_filename(const char *filepath,
+                              const int frame,
+                              char r_filepath_with_frames[1024])
 {
   BLI_strncpy(r_filepath_with_frames, filepath, FILE_MAX);
   BLI_path_extension_strip(r_filepath_with_frames);

source/blender/io/wavefront_obj/exporter/obj_exporter.hh

@@ -37,7 +37,7 @@ class OBJDepsgraph : NonMovable, NonCopyable {
 };
 
 /**
- * The main function for exporting a .obj file according to the given `export_parameters`.
+ * The main function for exporting a `.obj` file according to the given `export_parameters`.
  * It uses the context `C` to get the dependency graph, and from that, the `Scene`.
  * Depending on whether or not `export_params.export_animation` is set, it writes
  * either one file per animation frame, or just one file.
@@ -51,15 +51,15 @@ class OBJMesh;
 class OBJCurve;
 
 /**
- * Export a single frame of a .obj file, according to the given `export_parameters`.
+ * Export a single frame of a `.obj` file, according to the given `export_parameters`.
  * The frame state is given in `depsgraph`.
  * The output file name is given by `filepath`.
  * This function is normally called from `exporter_main`, but is exposed here for testing purposes.
  */
 /**
- * Export a single frame to a .OBJ file.
+ * Export a single frame to a `.OBJ` file.
  *
- * Conditionally write a .MTL file also.
+ * Conditionally write a `.MTL` file also.
  */
 void export_frame(Depsgraph *depsgraph,
                   const OBJExportParams &export_params,
@@ -72,22 +72,22 @@ void export_frame(Depsgraph *depsgraph,
  * exported, else all objects are to be exported. But only objects of type `OB_MESH`,
  * `OB_CURVES_LEGACY`, and `OB_SURF` are supported; the rest will be ignored. If
  * `export_params.export_curves_as_nurbs` is set, then curves of type `CU_NURBS` are exported in
- * curve form in the .obj file, otherwise they are converted to mesh and returned in the `OBJMesh`
- * vector. All other exportable types are always converted to mesh and returned in the `OBJMesh`
- * vector.
+ * curve form in the `.obj` file, otherwise they are converted to mesh and returned in the
+ * `OBJMesh` vector. All other exportable types are always converted to mesh and returned in the
+ * `OBJMesh` vector.
  */
 std::pair<Vector<std::unique_ptr<OBJMesh>>, Vector<std::unique_ptr<OBJCurve>>>
 filter_supported_objects(Depsgraph *depsgraph, const OBJExportParams &export_params);
 
 /**
- * Makes `r_filepath_with_frames` (which should point at a character array of size `FILE_MAX`)
- * be `filepath` with its "#" characters replaced by the number representing `frame`, and with
- * a .obj extension.
- */
-/**
- * Append the current frame number in the .OBJ file name.
+ * Append the current frame number in the `.OBJ` file name.
  *
- * \return Whether the filepath is in #FILE_MAX limits.
+ * \param r_filepath_with_frames: The result of the `filepath` with its "#" characters
+ * replaced by the number representing `frame`, and with an `.obj` extension.
+ *
+ * \return Whether the `filepath` is in #FILE_MAX limits.
  */
-bool append_frame_to_filename(const char *filepath, int frame, char *r_filepath_with_frames);
+bool append_frame_to_filename(const char *filepath,
+                              int frame,
+                              char r_filepath_with_frames[1024 /*FILE_MAX*/]);
 }  // namespace blender::io::obj

source/blender/io/wavefront_obj/importer/obj_import_file_reader.cc

@@ -849,8 +849,8 @@ void OBJParser::add_mtl_library(StringRef path)
 
 void OBJParser::add_default_mtl_library()
 {
-  /* Add any existing .mtl file that's with the same base name as the .obj file
-   * into candidate .mtl files to search through. This is not technically following the
+  /* Add any existing `.mtl` file that's with the same base name as the `.obj` file
+   * into candidate `.mtl` files to search through. This is not technically following the
    * spec, but the old python importer was doing it, and there are user files out there
    * that contain "mtllib bar.mtl" for a foo.obj, and depend on finding materials
    * from foo.mtl (see #97757). */

source/blender/io/wavefront_obj/importer/obj_import_mesh.cc

@@ -300,7 +300,7 @@ void MeshFromGeometry::create_uv_verts(Mesh *mesh)
 
   uv_map.finish();
 
-  /* If we have an object without UVs which resides in the same .obj file
+  /* If we have an object without UVs which resides in the same `.obj` file
    * as an object which *does* have UVs we can end up adding a UV layer
    * filled with zeroes.
    * We could maybe check before creating this layer but that would need

source/blender/io/wavefront_obj/tests/obj_importer_tests.cc

@@ -542,7 +542,7 @@ TEST_F(OBJImportTest, import_all_objects)
 {
   Expectation expect[] = {
       {"OBCube", OB_MESH, 8, 12, 6, 24, float3(1, 1, -1), float3(-1, 1, 1)},
-      /* .obj file has empty EmptyText and EmptyMesh objects; these are ignored and skipped */
+      /* `.obj` file has empty EmptyText and EmptyMesh objects; these are ignored and skipped. */
       {"OBBezierCurve", OB_MESH, 13, 12, 0, 0, float3(-1, -2, 0), float3(1, -2, 0)},
       {"OBBlankCube", OB_MESH, 8, 13, 7, 26, float3(1, 1, -1), float3(-1, 1, 1), float3(0, 0, 1)},
       {"OBMaterialCube",

source/blender/makesdna/intern/makesdna.cc

@@ -9,7 +9,7 @@
  *
  * \section aboutmakesdnac About makesdna tool
  *
- * `makesdna` creates a .c file with a long string of numbers that
+ * `makesdna` creates a `.c` file with a long string of numbers that
  * encode the Blender file format. It is fast, because it is basically
  * a binary dump. There are some details to mind when reconstructing
  * the file (endianness and byte-alignment).

source/blender/makesrna/intern/rna_fluid.cc

@@ -610,7 +610,7 @@ static const EnumPropertyItem *rna_Fluid_cachetype_volume_itemf(bContext * /*C*/
   RNA_enum_item_add(&item, &totitem, &tmp);
 #  endif
 
-  /* Support for deprecated .raw format. */
+  /* Support for deprecated `.raw` format. */
   FluidDomainSettings *fds = (FluidDomainSettings *)ptr->data;
   if (fds->cache_data_format == FLUID_DOMAIN_FILE_RAW ||
       fds->cache_noise_format == FLUID_DOMAIN_FILE_RAW)

source/blender/makesrna/intern/rna_ui.cc

@@ -1145,6 +1145,28 @@ static bool asset_shelf_poll(const bContext *C, const AssetShelfType *shelf_type
   return is_visible;
 }
 
+static const AssetWeakReference *asset_shelf_get_active_asset(const AssetShelfType *shelf_type)
+{
+  extern FunctionRNA rna_AssetShelf_get_active_asset_func;
+
+  PointerRNA ptr = RNA_pointer_create(nullptr, shelf_type->rna_ext.srna, nullptr); /* dummy */
+
+  FunctionRNA *func = &rna_AssetShelf_get_active_asset_func;
+
+  ParameterList list;
+  RNA_parameter_list_create(&list, &ptr, func);
+  shelf_type->rna_ext.call(nullptr, &ptr, func, &list);
+
+  void *ret;
+  RNA_parameter_get_lookup(&list, "asset_reference", &ret);
+  /* Get the value before freeing. */
+  AssetWeakReference *active_asset = *(AssetWeakReference **)ret;
+
+  RNA_parameter_list_free(&list);
+
+  return active_asset;
+}
+
 static void asset_shelf_draw_context_menu(const bContext *C,
                                           const AssetShelfType *shelf_type,
                                           const AssetRepresentationHandle *asset,
@@ -1175,23 +1197,12 @@ static bool rna_AssetShelf_unregister(Main *bmain, StructRNA *type)
     return false;
   }
 
-  SpaceType *space_type = BKE_spacetype_from_id(shelf_type->space_type);
-  if (!space_type) {
-    return false;
-  }
-
   blender::ed::asset::shelf::type_unlink(*bmain, *shelf_type);
 
   RNA_struct_free_extension(type, &shelf_type->rna_ext);
   RNA_struct_free(&BLENDER_RNA, type);
 
-  const auto it = std::find_if(
-      space_type->asset_shelf_types.begin(),
-      space_type->asset_shelf_types.end(),
-      [&](const std::unique_ptr<AssetShelfType> &type) { return type.get() == shelf_type; });
-  BLI_assert(it != space_type->asset_shelf_types.end());
-
-  space_type->asset_shelf_types.remove(it - space_type->asset_shelf_types.begin());
+  blender::ed::asset::shelf::type_unregister(*shelf_type);
 
   /* update while blender is running */
   WM_main_add_notifier(NC_WINDOW, nullptr);
@@ -1214,7 +1225,7 @@ static StructRNA *rna_AssetShelf_register(Main *bmain,
   dummy_shelf.type = shelf_type.get();
   PointerRNA dummy_shelf_ptr = RNA_pointer_create(nullptr, &RNA_AssetShelf, &dummy_shelf);
 
-  bool have_function[3];
+  bool have_function[4];
 
   /* validate the python class */
   if (validate(&dummy_shelf_ptr, data, have_function) != 0) {
@@ -1230,27 +1241,21 @@ static StructRNA *rna_AssetShelf_register(Main *bmain,
     return nullptr;
   }
 
-  SpaceType *space_type = BKE_spacetype_from_id(shelf_type->space_type);
-  if (!space_type) {
-    BLI_assert_unreachable();
-    return nullptr;
-  }
-
   /* Check if we have registered this asset shelf type before, and remove it. */
-  for (std::unique_ptr<AssetShelfType> &iter_shelf_type : space_type->asset_shelf_types) {
-    if (STREQ(iter_shelf_type->idname, shelf_type->idname)) {
-      if (iter_shelf_type->rna_ext.srna) {
-        BKE_reportf(reports,
-                    RPT_INFO,
-                    "Registering asset shelf class: '%s' has been registered before, "
-                    "unregistering previous",
-                    shelf_type->idname);
+  {
+    AssetShelfType *existing_shelf_type = blender::ed::asset::shelf::type_find_from_idname(
+        shelf_type->idname);
+    if (existing_shelf_type && existing_shelf_type->rna_ext.srna) {
+      BKE_reportf(reports,
+                  RPT_INFO,
+                  "Registering asset shelf class: '%s' has been registered before, "
+                  "unregistering previous",
+                  shelf_type->idname);
 
-        rna_AssetShelf_unregister(bmain, iter_shelf_type->rna_ext.srna);
-      }
-      break;
+      rna_AssetShelf_unregister(bmain, existing_shelf_type->rna_ext.srna);
     }
   }
+
   if (!RNA_struct_available_or_report(reports, shelf_type->idname)) {
     return nullptr;
   }
@@ -1267,11 +1272,12 @@ static StructRNA *rna_AssetShelf_register(Main *bmain,
 
   shelf_type->poll = have_function[0] ? asset_shelf_poll : nullptr;
   shelf_type->asset_poll = have_function[1] ? asset_shelf_asset_poll : nullptr;
-  shelf_type->draw_context_menu = have_function[2] ? asset_shelf_draw_context_menu : nullptr;
+  shelf_type->get_active_asset = have_function[2] ? asset_shelf_get_active_asset : nullptr;
+  shelf_type->draw_context_menu = have_function[3] ? asset_shelf_draw_context_menu : nullptr;
 
   StructRNA *srna = shelf_type->rna_ext.srna;
 
-  space_type->asset_shelf_types.append(std::move(shelf_type));
+  blender::ed::asset::shelf::type_register(std::move(shelf_type));
 
   /* update while blender is running */
   WM_main_add_notifier(NC_WINDOW, nullptr);
@@ -1279,6 +1285,24 @@ static StructRNA *rna_AssetShelf_register(Main *bmain,
   return srna;
 }
 
+static void rna_AssetShelf_activate_operator_get(PointerRNA *ptr, char *value)
+{
+  AssetShelf *shelf = static_cast<AssetShelf *>(ptr->data);
+  strcpy(value, shelf->type->activate_operator.c_str());
+}
+
+static int rna_AssetShelf_activate_operator_length(PointerRNA *ptr)
+{
+  AssetShelf *shelf = static_cast<AssetShelf *>(ptr->data);
+  return shelf->type->activate_operator.size();
+}
+
+static void rna_AssetShelf_activate_operator_set(PointerRNA *ptr, const char *value)
+{
+  AssetShelf *shelf = static_cast<AssetShelf *>(ptr->data);
+  shelf->type->activate_operator = value;
+}
+
 static StructRNA *rna_AssetShelf_refine(PointerRNA *shelf_ptr)
 {
   AssetShelf *shelf = (AssetShelf *)shelf_ptr->data;
@@ -2309,6 +2333,17 @@ static void rna_def_asset_shelf(BlenderRNA *brna)
   RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL | PROP_ENUM_FLAG);
   RNA_def_property_ui_text(prop, "Options", "Options for this asset shelf type");
 
+  prop = RNA_def_property(srna, "bl_activate_operator", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_funcs(prop,
+                                "rna_AssetShelf_activate_operator_get",
+                                "rna_AssetShelf_activate_operator_length",
+                                "rna_AssetShelf_activate_operator_set");
+  RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
+  RNA_def_property_ui_text(
+      prop,
+      "Activate Operator",
+      "Operator to call when activating an item with asset reference properties");
+
   prop = RNA_def_property(srna, "bl_default_preview_size", PROP_INT, PROP_UNSIGNED);
   RNA_def_property_int_sdna(prop, nullptr, "type->default_preview_size");
   RNA_def_property_range(prop, 32, 256);
@@ -2337,6 +2372,19 @@ static void rna_def_asset_shelf(BlenderRNA *brna)
   parm = RNA_def_pointer(func, "asset", "AssetRepresentation", "", "");
   RNA_def_parameter_flags(parm, PropertyFlag(0), PARM_REQUIRED);
 
+  func = RNA_def_function(srna, "get_active_asset", nullptr);
+  RNA_def_function_ui_description(
+      func,
+      "Return a reference to the asset that should be highlighted as active in the asset shelf");
+  RNA_def_function_flag(func, FUNC_NO_SELF | FUNC_REGISTER_OPTIONAL);
+  /* return type */
+  parm = RNA_def_pointer(func,
+                         "asset_reference",
+                         "AssetWeakReference",
+                         "",
+                         "The weak reference to the asset to be hightlighted as active, or None");
+  RNA_def_function_return(func, parm);
+
   func = RNA_def_function(srna, "draw_context_menu", nullptr);
   RNA_def_function_ui_description(
       func, "Draw UI elements into the context menu UI layout displayed on right click");

source/blender/python/generic/py_capi_utils.cc

@@ -1102,11 +1102,12 @@ PyObject *PyC_DefaultNameSpace(const char *filename)
   PyDict_SetItemString(modules, "__main__", mod_main);
   Py_DECREF(mod_main); /* `sys.modules` owns now. */
   PyModule_AddStringConstant(mod_main, "__name__", "__main__");
-  if (filename) {
-    /* __file__ mainly for nice UI'ness
-     * NOTE: this won't map to a real file when executing text-blocks and buttons. */
-    PyModule_AddObject(mod_main, "__file__", PyC_UnicodeFromBytes(filename));
-  }
+
+  /* This won't map to a real file when executing text-blocks and buttons.
+   * In this case an identifier is typically used that is surrounded by angle-brackets.
+   * It's mainly helpful for the UI and messages to show *something*. */
+  PyModule_AddObject(mod_main, "__file__", PyC_UnicodeFromBytes(filename));
+
   PyModule_AddObject(mod_main, "__builtins__", builtins);
   Py_INCREF(builtins); /* AddObject steals a reference */
   return PyModule_GetDict(mod_main);
@@ -1132,7 +1133,7 @@ bool PyC_NameSpace_ImportArray(PyObject *py_dict, const char *imports[])
   return true;
 }
 
-void PyC_MainModule_Backup(PyObject **r_main_mod)
+PyObject *PyC_MainModule_Backup()
 {
   PyObject *modules = PyImport_GetModuleDict();
   PyObject *main_mod = PyDict_GetItemString(modules, "__main__");
@@ -1141,7 +1142,7 @@ void PyC_MainModule_Backup(PyObject **r_main_mod)
     /* is transferred back to `sys.modules`. */
     Py_INCREF(main_mod);
   }
-  *r_main_mod = main_mod;
+  return main_mod;
 }
 
 void PyC_MainModule_Restore(PyObject *main_mod)
@@ -1466,45 +1467,62 @@ PyObject *PyC_FlagSet_FromBitfield(PyC_FlagSet *items, int flag)
 /** \name Run String (Evaluate to Primitive Types)
  * \{ */
 
+static PyObject *pyc_run_string_as_py_object(const char *imports[],
+                                             const char *imports_star[],
+                                             const char *expr,
+                                             const char *filename)
+    ATTR_NONNULL(3, 4) ATTR_WARN_UNUSED_RESULT;
+static PyObject *pyc_run_string_as_py_object(const char *imports[],
+                                             const char *imports_star[],
+                                             const char *expr,
+                                             const char *filename)
+{
+  PyObject *main_mod = PyC_MainModule_Backup();
+
+  PyObject *py_dict = PyC_DefaultNameSpace(filename);
+
+  if (imports_star) {
+    for (int i = 0; imports_star[i]; i++) {
+      PyObject *mod = PyImport_ImportModule("math");
+      if (mod) {
+        /* Don't overwrite existing values (override=0). */
+        PyDict_Merge(py_dict, PyModule_GetDict(mod), 0);
+        Py_DECREF(mod);
+      }
+      else { /* Highly unlikely but possibly. */
+        PyErr_Print();
+        PyErr_Clear();
+      }
+    }
+  }
+
+  PyObject *retval;
+  if (imports && !PyC_NameSpace_ImportArray(py_dict, imports)) {
+    retval = nullptr; /* Failure. */
+  }
+  else {
+    retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict);
+  }
+
+  PyC_MainModule_Restore(main_mod);
+
+  return retval;
+}
+
 bool PyC_RunString_AsNumber(const char *imports[],
                             const char *expr,
                             const char *filename,
                             double *r_value)
 {
-  PyObject *py_dict, *mod, *retval;
-  bool ok = true;
-  PyObject *main_mod = nullptr;
-
-  PyC_MainModule_Backup(&main_mod);
-
-  py_dict = PyC_DefaultNameSpace(filename);
-
-  mod = PyImport_ImportModule("math");
-  if (mod) {
-    PyDict_Merge(py_dict, PyModule_GetDict(mod), 0); /* 0 - don't overwrite existing values */
-    Py_DECREF(mod);
-  }
-  else { /* highly unlikely but possibly */
-    PyErr_Print();
-    PyErr_Clear();
-  }
-
-  if (imports && !PyC_NameSpace_ImportArray(py_dict, imports)) {
-    ok = false;
-  }
-  else if ((retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict)) == nullptr) {
-    ok = false;
-  }
-  else {
+  int ok = -1;
+  const char *imports_star[] = {"math", nullptr};
+  if (PyObject *retval = pyc_run_string_as_py_object(imports, imports_star, expr, filename)) {
     double val;
 
     if (PyTuple_Check(retval)) {
-      /* Users my have typed in 10km, 2m
-       * add up all values */
-      int i;
+      /* Users my have typed in `10km, 2m`, accumulate all values. */
       val = 0.0;
-
-      for (i = 0; i < PyTuple_GET_SIZE(retval); i++) {
+      for (int i = 0; i < PyTuple_GET_SIZE(retval); i++) {
         const double val_item = PyFloat_AsDouble(PyTuple_GET_ITEM(retval, i));
         if (val_item == -1 && PyErr_Occurred()) {
           val = -1;
@@ -1523,15 +1541,18 @@ bool PyC_RunString_AsNumber(const char *imports[],
     }
     else if (!isfinite(val)) {
       *r_value = 0.0;
+      ok = true;
     }
     else {
       *r_value = val;
+      ok = true;
     }
   }
-
-  PyC_MainModule_Restore(main_mod);
-
-  return ok;
+  else {
+    ok = false;
+  }
+  BLI_assert(ok != -1);
+  return bool(ok);
 }
 
 bool PyC_RunString_AsIntPtr(const char *imports[],
@@ -1539,36 +1560,23 @@ bool PyC_RunString_AsIntPtr(const char *imports[],
                             const char *filename,
                             intptr_t *r_value)
 {
-  PyObject *py_dict, *retval;
-  bool ok = true;
-  PyObject *main_mod = nullptr;
-
-  PyC_MainModule_Backup(&main_mod);
-
-  py_dict = PyC_DefaultNameSpace(filename);
-
-  if (imports && !PyC_NameSpace_ImportArray(py_dict, imports)) {
-    ok = false;
-  }
-  else if ((retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict)) == nullptr) {
-    ok = false;
-  }
-  else {
-    intptr_t val;
-
-    val = intptr_t(PyLong_AsVoidPtr(retval));
+  int ok = -1;
+  if (PyObject *retval = pyc_run_string_as_py_object(imports, nullptr, expr, filename)) {
+    const intptr_t val = intptr_t(PyLong_AsVoidPtr(retval));
     if (val == 0 && PyErr_Occurred()) {
       ok = false;
     }
     else {
       *r_value = val;
+      ok = true;
     }
 
     Py_DECREF(retval);
   }
-
-  PyC_MainModule_Restore(main_mod);
-
+  else {
+    ok = false;
+  }
+  BLI_assert(ok != -1);
   return ok;
 }
 
@@ -1578,25 +1586,10 @@ bool PyC_RunString_AsStringAndSize(const char *imports[],
                                    char **r_value,
                                    size_t *r_value_size)
 {
-  PyObject *py_dict, *retval;
-  bool ok = true;
-  PyObject *main_mod = nullptr;
-
-  PyC_MainModule_Backup(&main_mod);
-
-  py_dict = PyC_DefaultNameSpace(filename);
-
-  if (imports && !PyC_NameSpace_ImportArray(py_dict, imports)) {
-    ok = false;
-  }
-  else if ((retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict)) == nullptr) {
-    ok = false;
-  }
-  else {
-    const char *val;
+  int ok = -1;
+  if (PyObject *retval = pyc_run_string_as_py_object(imports, nullptr, expr, filename)) {
     Py_ssize_t val_len;
-
-    val = PyUnicode_AsUTF8AndSize(retval, &val_len);
+    const char *val = PyUnicode_AsUTF8AndSize(retval, &val_len);
     if (val == nullptr && PyErr_Occurred()) {
       ok = false;
     }
@@ -1605,13 +1598,14 @@ bool PyC_RunString_AsStringAndSize(const char *imports[],
       memcpy(val_alloc, val, val_len + 1);
       *r_value = val_alloc;
       *r_value_size = val_len;
+      ok = true;
     }
-
     Py_DECREF(retval);
   }
-
-  PyC_MainModule_Restore(main_mod);
-
+  else {
+    ok = false;
+  }
+  BLI_assert(ok != -1);
   return ok;
 }
 
@@ -1630,30 +1624,16 @@ bool PyC_RunString_AsStringAndSizeOrNone(const char *imports[],
                                          char **r_value,
                                          size_t *r_value_size)
 {
-  PyObject *py_dict, *retval;
-  bool ok = true;
-  PyObject *main_mod = nullptr;
-
-  PyC_MainModule_Backup(&main_mod);
-
-  py_dict = PyC_DefaultNameSpace(filename);
-
-  if (imports && !PyC_NameSpace_ImportArray(py_dict, imports)) {
-    ok = false;
-  }
-  else if ((retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict)) == nullptr) {
-    ok = false;
-  }
-  else {
+  int ok = -1;
+  if (PyObject *retval = pyc_run_string_as_py_object(imports, nullptr, expr, filename)) {
     if (retval == Py_None) {
       *r_value = nullptr;
       *r_value_size = 0;
+      ok = true;
     }
     else {
-      const char *val;
       Py_ssize_t val_len;
-
-      val = PyUnicode_AsUTF8AndSize(retval, &val_len);
+      const char *val = PyUnicode_AsUTF8AndSize(retval, &val_len);
       if (val == nullptr && PyErr_Occurred()) {
         ok = false;
       }
@@ -1662,15 +1642,16 @@ bool PyC_RunString_AsStringAndSizeOrNone(const char *imports[],
         memcpy(val_alloc, val, val_len + 1);
         *r_value = val_alloc;
         *r_value_size = val_len;
+        ok = true;
       }
     }
-
     Py_DECREF(retval);
   }
-
-  PyC_MainModule_Restore(main_mod);
-
-  return ok;
+  else {
+    ok = false;
+  }
+  BLI_assert(ok != -1);
+  return bool(ok);
 }
 
 bool PyC_RunString_AsStringOrNone(const char *imports[],
@@ -1808,10 +1789,6 @@ uint32_t PyC_Long_AsU32(PyObject *value)
   return uint32_t(test);
 }
 
-/* #PyLong_AsUnsignedLongLong, unlike #PyLong_AsLongLong, does not fall back to calling
- * #PyNumber_Index when its argument is not a `PyLongObject` instance. To match parsing signed
- * integer types with #PyLong_AsLongLong, this function performs the #PyNumber_Index fallback, if
- * necessary, before calling #PyLong_AsUnsignedLongLong. */
 uint64_t PyC_Long_AsU64(PyObject *value)
 {
   if (value == nullptr) {

source/blender/python/generic/py_capi_utils.h

@@ -169,11 +169,11 @@ int PyC_ParseUnicodeAsBytesAndSize_OrNone(PyObject *o, void *p);
  * >> print(__import__("__main__").foo)
  *
  * NOTE: this overwrites __main__ which gives problems with nested calls.
- * be sure to run PyC_MainModule_Backup & PyC_MainModule_Restore if there is
+ * be sure to run #PyC_MainModule_Backup & #PyC_MainModule_Restore if there is
  * any chance that python is in the call stack.
  */
-PyObject *PyC_DefaultNameSpace(const char *filename);
-void PyC_RunQuicky(const char *filepath, int n, ...);
+PyObject *PyC_DefaultNameSpace(const char *filename) ATTR_NONNULL(1) ATTR_WARN_UNUSED_RESULT;
+void PyC_RunQuicky(const char *filepath, int n, ...) ATTR_NONNULL(1);
 /**
  * Import `imports` into `py_dict`.
  *
@@ -187,7 +187,7 @@ bool PyC_NameSpace_ImportArray(PyObject *py_dict, const char *imports[]);
 /**
  * #PyC_MainModule_Restore MUST be called after #PyC_MainModule_Backup.
  */
-void PyC_MainModule_Backup(PyObject **r_main_mod);
+PyObject *PyC_MainModule_Backup() ATTR_WARN_UNUSED_RESULT;
 void PyC_MainModule_Restore(PyObject *main_mod);
 
 bool PyC_IsInterpreterActive(void);
@@ -223,11 +223,11 @@ PyObject *PyC_FlagSet_FromBitfield(PyC_FlagSet *items, int flag);
 bool PyC_RunString_AsNumber(const char **imports,
                             const char *expr,
                             const char *filename,
-                            double *r_value);
+                            double *r_value) ATTR_NONNULL(2, 3, 4) ATTR_WARN_UNUSED_RESULT;
 bool PyC_RunString_AsIntPtr(const char **imports,
                             const char *expr,
                             const char *filename,
-                            intptr_t *r_value);
+                            intptr_t *r_value) ATTR_NONNULL(2, 3, 4) ATTR_WARN_UNUSED_RESULT;
 /**
  * \param r_value_size: The length of the string assigned: `strlen(*r_value)`.
  */
@@ -235,11 +235,12 @@ bool PyC_RunString_AsStringAndSize(const char **imports,
                                    const char *expr,
                                    const char *filename,
                                    char **r_value,
-                                   size_t *r_value_size);
+                                   size_t *r_value_size)
+    ATTR_NONNULL(2, 3, 4, 5) ATTR_WARN_UNUSED_RESULT;
 bool PyC_RunString_AsString(const char **imports,
                             const char *expr,
                             const char *filename,
-                            char **r_value);
+                            char **r_value) ATTR_NONNULL(2, 3, 4) ATTR_WARN_UNUSED_RESULT;
 
 /**
  * \param r_value_size: The length of the string assigned: `strlen(*r_value)`.
@@ -248,11 +249,12 @@ bool PyC_RunString_AsStringAndSizeOrNone(const char **imports,
                                          const char *expr,
                                          const char *filename,
                                          char **r_value,
-                                         size_t *r_value_size);
+                                         size_t *r_value_size)
+    ATTR_NONNULL(2, 3, 4) ATTR_WARN_UNUSED_RESULT;
 bool PyC_RunString_AsStringOrNone(const char **imports,
                                   const char *expr,
                                   const char *filename,
-                                  char **r_value);
+                                  char **r_value) ATTR_NONNULL(2, 3, 4) ATTR_WARN_UNUSED_RESULT;
 
 /**
  * Use with PyArg_ParseTuple's "O&" formatting.
@@ -315,13 +317,21 @@ int32_t PyC_Long_AsI32(PyObject *value);
 int64_t PyC_Long_AsI64(PyObject *value);
 #endif
 
-/* Unlike Python's #PyLong_AsUnsignedLong and #PyLong_AsUnsignedLongLong, these unsigned integer
+/**
+ * Unlike Python's #PyLong_AsUnsignedLong and #PyLong_AsUnsignedLongLong, these unsigned integer
  * parsing functions fall back to calling #PyNumber_Index when their argument is not a
  * `PyLongObject`. This matches Python's signed integer parsing functions which also fall back to
- * calling #PyNumber_Index. */
+ * calling #PyNumber_Index.
+ */
 uint8_t PyC_Long_AsU8(PyObject *value);
 uint16_t PyC_Long_AsU16(PyObject *value);
 uint32_t PyC_Long_AsU32(PyObject *value);
+/**
+ * #PyLong_AsUnsignedLongLong, unlike #PyLong_AsLongLong, does not fall back to calling
+ * #PyNumber_Index when its argument is not a `PyLongObject` instance. To match parsing signed
+ * integer types with #PyLong_AsLongLong, this function performs the #PyNumber_Index fallback, if
+ * necessary, before calling #PyLong_AsUnsignedLongLong.
+ */
 uint64_t PyC_Long_AsU64(PyObject *value);
 
 /* inline so type signatures match as expected */

source/blender/python/intern/bpy_interface_run.cc

@@ -144,7 +144,6 @@ static bool python_script_exec(
     bContext *C, const char *filepath, Text *text, ReportList *reports, const bool do_jump)
 {
   Main *bmain_old = CTX_data_main(C);
-  PyObject *main_mod = nullptr;
   PyObject *py_dict = nullptr, *py_result = nullptr;
   PyGILState_STATE gilstate;
 
@@ -160,7 +159,7 @@ static bool python_script_exec(
 
   bpy_context_set(C, &gilstate);
 
-  PyC_MainModule_Backup(&main_mod);
+  PyObject *main_mod = PyC_MainModule_Backup();
 
   if (text) {
     bpy_text_filepath_get(filepath_dummy, sizeof(filepath_dummy), bmain_old, text);
@@ -278,7 +277,6 @@ static bool bpy_run_string_impl(bContext *C,
 {
   BLI_assert(expr);
   PyGILState_STATE gilstate;
-  PyObject *main_mod = nullptr;
   PyObject *py_dict, *retval;
   bool ok = true;
 
@@ -288,7 +286,7 @@ static bool bpy_run_string_impl(bContext *C,
 
   bpy_context_set(C, &gilstate);
 
-  PyC_MainModule_Backup(&main_mod);
+  PyObject *main_mod = PyC_MainModule_Backup();
 
   py_dict = PyC_DefaultNameSpace("<blender string>");
 

source/blender/python/intern/bpy_rna_ui.cc

@@ -31,8 +31,7 @@ static PyObject *bpy_rna_uilayout_introspect(PyObject *self)
   uiLayout *layout = static_cast<uiLayout *>(pyrna->ptr.data);
 
   const char *expr = UI_layout_introspect(layout);
-  PyObject *main_mod = nullptr;
-  PyC_MainModule_Backup(&main_mod);
+  PyObject *main_mod = PyC_MainModule_Backup();
   PyObject *py_dict = PyC_DefaultNameSpace("<introspect>");
   PyObject *result = PyRun_String(expr, Py_eval_input, py_dict, py_dict);
   MEM_freeN((void *)expr);

source/blender/windowmanager/intern/wm_uilist_type.cc

@@ -81,8 +81,8 @@ static void wm_uilisttype_unlink_from_area(const uiListType *ult, ScrArea *area)
  * For all lists representing \a ult, clear their `uiListType` pointer. Use when a list-type is
  * deleted, so that the UI doesn't keep references to it.
  *
- * This is a common pattern for unregistering (usually .py defined) types at runtime, e.g. see
- * #WM_gizmomaptype_group_unlink().
+ * This is a common pattern for unregistering (usually `.py` defined) types at runtime, e.g.
+ * see #WM_gizmomaptype_group_unlink().
  * Note that unlike in some other cases using this pattern, we don't actually free the lists with
  * type \a ult, we just clear the reference to the type. That's because UI-Lists are written to
  * files and we don't want them to get lost together with their (user visible) settings.