source/blender/editors/interface/interface_drag.cc

@@ -64,7 +64,7 @@ void UI_but_drag_set_path(uiBut *but, const char *path)
   if (but->dragflag & UI_BUT_DRAGPOIN_FREE) {
     WM_drag_data_free(but->dragtype, but->dragpoin);
   }
-  but->dragpoin = WM_drag_create_path_data(path);
+  but->dragpoin = WM_drag_create_path_data(blender::Span(&path, 1));
   but->dragflag |= UI_BUT_DRAGPOIN_FREE;
 }
 

source/blender/editors/screen/screen_ops.cc

@@ -5907,7 +5907,7 @@ static bool blend_file_drop_poll(bContext * /*C*/, wmDrag *drag, const wmEvent *
 static void blend_file_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
 {
   /* copy drag path to properties */
-  RNA_string_set(drop->ptr, "filepath", WM_drag_get_path(drag));
+  RNA_string_set(drop->ptr, "filepath", WM_drag_get_paths(drag)[0].c_str());
 }
 
 void ED_keymap_screen(wmKeyConfig *keyconf)

source/blender/editors/space_clip/space_clip.cc

@@ -536,7 +536,8 @@ static void clip_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
   PointerRNA itemptr;
   char dir[FILE_MAX], file[FILE_MAX];
 
-  BLI_path_split_dir_file(WM_drag_get_path(drag), dir, sizeof(dir), file, sizeof(file));
+  BLI_path_split_dir_file(
+      WM_drag_get_paths(drag)[0].c_str(), dir, sizeof(dir), file, sizeof(file));
 
   RNA_string_set(drop->ptr, "directory", dir);
 

source/blender/editors/space_console/space_console.cc

@@ -174,7 +174,7 @@ static bool path_drop_poll(bContext * /*C*/, wmDrag *drag, const wmEvent * /*eve
 static void path_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
 {
   char pathname[FILE_MAX + 2];
-  SNPRINTF(pathname, "\"%s\"", WM_drag_get_path(drag));
+  SNPRINTF(pathname, "\"%s\"", WM_drag_get_paths(drag)[0].c_str());
   RNA_string_set(drop->ptr, "text", pathname);
 }
 

source/blender/editors/space_file/space_file.cc

@@ -799,7 +799,7 @@ static bool filepath_drop_poll(bContext *C, wmDrag *drag, const wmEvent * /*even
 
 static void filepath_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
 {
-  RNA_string_set(drop->ptr, "filepath", WM_drag_get_path(drag));
+  RNA_string_set(drop->ptr, "filepath", WM_drag_get_paths(drag)[0].c_str());
 }
 
 /* region dropbox definition */

source/blender/editors/space_image/space_image.cc

@@ -268,7 +268,7 @@ static bool image_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 static void image_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
 {
   /* copy drag path to properties */
-  RNA_string_set(drop->ptr, "filepath", WM_drag_get_path(drag));
+  RNA_string_set(drop->ptr, "filepath", WM_drag_get_paths(drag)[0].c_str());
 }
 
 /* area+region dropbox definition */

source/blender/editors/space_node/space_node.cc

@@ -725,9 +725,9 @@ static void node_id_path_drop_copy(bContext *C, wmDrag *drag, wmDropBox *drop)
     return;
   }
 
-  const char *path = WM_drag_get_path(drag);
-  if (path) {
-    RNA_string_set(drop->ptr, "filepath", path);
+  const auto paths = WM_drag_get_paths(drag);
+  if (paths.begin()) {
+    RNA_string_set(drop->ptr, "filepath", paths[0].c_str());
     RNA_struct_property_unset(drop->ptr, "name");
     return;
   }

source/blender/editors/space_sequencer/sequencer_drag_drop.cc

@@ -249,17 +249,17 @@ static void sequencer_drop_copy(bContext *C, wmDrag *drag, wmDropBox *drop)
     return;
   }
 
-  const char *path = WM_drag_get_path(drag);
+  const auto paths = WM_drag_get_paths(drag);
   /* Path dropped. */
-  if (path) {
+  if (paths.begin()) {
     if (RNA_struct_find_property(drop->ptr, "filepath")) {
-      RNA_string_set(drop->ptr, "filepath", path);
+      RNA_string_set(drop->ptr, "filepath", paths[0].c_str());
     }
     if (RNA_struct_find_property(drop->ptr, "directory")) {
       PointerRNA itemptr;
       char dir[FILE_MAX], file[FILE_MAX];
 
-      BLI_path_split_dir_file(path, dir, sizeof(dir), file, sizeof(file));
+      BLI_path_split_dir_file(paths[0].c_str(), dir, sizeof(dir), file, sizeof(file));
 
       RNA_string_set(drop->ptr, "directory", dir);
 
@@ -337,7 +337,7 @@ static void get_drag_path(const bContext *C, wmDrag *drag, char r_path[FILE_MAX]
     BLI_path_abs(r_path, BKE_main_blendfile_path_from_global());
   }
   else {
-    BLI_strncpy(r_path, WM_drag_get_path(drag), FILE_MAX);
+    BLI_strncpy(r_path, WM_drag_get_paths(drag)[0].c_str(), FILE_MAX);
   }
 }
 

source/blender/editors/space_text/space_text.cc

@@ -315,7 +315,7 @@ static bool text_drop_poll(bContext * /*C*/, wmDrag *drag, const wmEvent * /*eve
 static void text_drop_copy(bContext * /*C*/, wmDrag *drag, wmDropBox *drop)
 {
   /* copy drag path to properties */
-  RNA_string_set(drop->ptr, "filepath", WM_drag_get_path(drag));
+  RNA_string_set(drop->ptr, "filepath", WM_drag_get_paths(drag)[0].c_str());
 }
 
 static bool text_drop_paste_poll(bContext * /*C*/, wmDrag *drag, const wmEvent * /*event*/)

source/blender/editors/space_view3d/space_view3d.cc

@@ -927,9 +927,9 @@ static void view3d_id_path_drop_copy(bContext *C, wmDrag *drag, wmDropBox *drop)
     RNA_struct_property_unset(drop->ptr, "filepath");
     return;
   }
-  const char *path = WM_drag_get_path(drag);
-  if (path) {
-    RNA_string_set(drop->ptr, "filepath", path);
+  const auto paths = WM_drag_get_paths(drag);
+  if (paths.begin()) {
+    RNA_string_set(drop->ptr, "filepath", paths[0].c_str());
     RNA_struct_property_unset(drop->ptr, "image");
   }
 }

source/blender/windowmanager/WM_api.hh

@@ -1393,13 +1393,13 @@ const ListBase *WM_drag_asset_list_get(const wmDrag *drag);
 
 const char *WM_drag_get_item_name(wmDrag *drag);
 
-/* Path drag and drop. */
+/* Paths drag and drop. */
 /**
- * \param path: The path to drag. Value will be copied into the drag data so the passed string may
- *              be destructed.
+ * \param paths: The paths to drag. Values will be copied into the drag data so the passed strings
+ * may be destructed. Only paths that share the same extension of the first file will be copied.
  */
-wmDragPath *WM_drag_create_path_data(const char *path);
-const char *WM_drag_get_path(const wmDrag *drag);
+wmDragPath *WM_drag_create_path_data(blender::Span<const char *> paths);
+const blender::Span<std::string> WM_drag_get_paths(const wmDrag *drag);
 /**
  * Note that even though the enum return type uses bit-flags, this should never have multiple
  * type-bits set, so `ELEM()` like comparison is possible.

source/blender/windowmanager/WM_types.hh

@@ -106,6 +106,7 @@ struct wmWindowManager;
 
 #include "BLI_compiler_attrs.h"
 #include "BLI_utildefines.h"
+#include "BLI_vector.hh"
 #include "DNA_listBase.h"
 #include "DNA_uuid_types.h"
 #include "DNA_vec_types.h"
@@ -1125,10 +1126,15 @@ struct wmDragAssetListItem {
 };
 
 struct wmDragPath {
-  char *path;
+  const blender::Vector<std::string> paths;
   /* Note that even though the enum type uses bit-flags, this should never have multiple type-bits
    * set, so `ELEM()` like comparison is possible. */
-  int file_type; /* eFileSel_File_Types */
+  const int file_type; /* eFileSel_File_Types */
+  const std::string tooltip;
+  wmDragPath(const blender::Vector<std::string> &paths, const std::string &tooltip, int file_type)
+      : paths(std::move(paths)), file_type(file_type), tooltip(tooltip)
+  {
+  }
 };
 
 struct wmDragGreasePencilLayer {

source/blender/windowmanager/intern/wm_dragdrop.cc

@@ -760,29 +760,45 @@ const ListBase *WM_drag_asset_list_get(const wmDrag *drag)
   return &drag->asset_items;
 }
 
-wmDragPath *WM_drag_create_path_data(const char *path)
+wmDragPath *WM_drag_create_path_data(blender::Span<const char *> _paths)
 {
-  wmDragPath *path_data = MEM_new<wmDragPath>("wmDragPath");
-  path_data->path = BLI_strdup(path);
-  path_data->file_type = ED_path_extension_type(path);
+  const char *ext = BLI_path_extension(_paths[0]);
+  blender::Vector<std::string> paths;
+  for (auto path : _paths) {
+    if (STREQ(ext, BLI_path_extension(path))) {
+      paths.append(path);
+    }
+  }
+  char *tooltip;
+  if (_paths.size() == 1) {
+    tooltip = BLI_strdup(_paths[0]);
+  }
+  else {
+    tooltip = BLI_sprintfN(TIP_("Dragging %d %s files."), paths.size());
+  }
+
+  wmDragPath *path_data = MEM_new<wmDragPath>(
+      "wmDragPath", paths, tooltip, ED_path_extension_type(_paths[0]));
+
+  MEM_freeN(tooltip);
+
   return path_data;
 }
 
 static void wm_drag_free_path_data(wmDragPath **path_data)
 {
-  MEM_freeN((*path_data)->path);
   MEM_delete(*path_data);
   *path_data = nullptr;
 }
 
-const char *WM_drag_get_path(const wmDrag *drag)
+const blender::Span<std::string> WM_drag_get_paths(const wmDrag *drag)
 {
   if (drag->type != WM_DRAG_PATH) {
-    return nullptr;
+    return blender::Span<std::string>();
   }
 
   const wmDragPath *path_data = static_cast<const wmDragPath *>(drag->poin);
-  return path_data->path;
+  return path_data->paths.as_span();
 }
 
 int WM_drag_get_path_file_type(const wmDrag *drag)
@@ -846,7 +862,7 @@ const char *WM_drag_get_item_name(wmDrag *drag)
     }
     case WM_DRAG_PATH: {
       const wmDragPath *path_drag_data = static_cast<const wmDragPath *>(drag->poin);
-      return path_drag_data->path;
+      return path_drag_data->tooltip.c_str();
     }
     case WM_DRAG_NAME:
       return static_cast<const char *>(drag->poin);
@@ -1039,8 +1055,9 @@ void wm_drags_draw(bContext *C, wmWindow *win)
         wmWindowViewport(win);
       }
 
-      /* Drawing should be allowed to assume the context from handling and polling (that's why we
-       * restore it above). */
+      /* Drawing should be allowed to assume the context from
+       * handling and polling (that's why we restore it
+       * above). */
       if (drag->drop_state.active_dropbox->draw_droptip) {
         drag->drop_state.active_dropbox->draw_droptip(C, win, drag, xy);
         continue;

source/blender/windowmanager/intern/wm_window.cc

@@ -1512,14 +1512,14 @@ wm_window_swap_buffers(win);
         if (ddd->dataType == GHOST_kDragnDropTypeFilenames) {
           GHOST_TStringArray *stra = static_cast<GHOST_TStringArray *>(ddd->data);
 
-          for (int a = 0; a < stra->count; a++) {
-            printf("drop file %s\n", stra->strings[a]);
+          if (stra->count) {
+            printf("drop file %s\n", stra->strings[0]);
             /* try to get icon type from extension */
-            int icon = ED_file_extension_icon((char *)stra->strings[a]);
-            wmDragPath *path_data = WM_drag_create_path_data((char *)stra->strings[a]);
+            int icon = ED_file_extension_icon((char *)stra->strings[0]);
+            wmDragPath *path_data = WM_drag_create_path_data(
+                blender::Span((char **)stra->strings, stra->count));
             WM_event_start_drag(C, icon, WM_DRAG_PATH, path_data, 0.0, WM_DRAG_NOP);
             /* void poin should point to string, it makes a copy */
-            break; /* only one drop element supported now */
           }
         }