source/blender/blenkernel/BKE_attribute.h

@@ -9,6 +9,8 @@
 
 #pragma once
 
+#include "DNA_ID.h"
+
 #include "BLI_sys_types.h"
 
 #include "BKE_customdata.h"
@@ -22,6 +24,10 @@ struct CustomDataLayer;
 struct ID;
 struct ReportList;
 
+typedef struct AttrUniqueData {
+  ID *id;
+} AttrUniqueData;
+
 /** #Attribute.domain */
 typedef enum eAttrDomain {
   ATTR_DOMAIN_AUTO = -1,    /* Use for nodes to choose automatically based on other data. */
@@ -117,6 +123,7 @@ void BKE_id_attributes_default_color_set(struct ID *id, const char *name);
 
 struct CustomDataLayer *BKE_id_attributes_color_find(const struct ID *id, const char *name);
 
+bool BKE_id_attribute_unique_name_check(void *arg, const char *name);
 bool BKE_id_attribute_calc_unique_name(struct ID *id, const char *name, char *outname);
 
 const char *BKE_uv_map_vert_select_name_get(const char *uv_map_name, char *buffer);

source/blender/blenkernel/BKE_deform.h

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include "DNA_object_types.h"
+
 #ifdef __cplusplus
 #  include "BLI_math_vector_types.hh"
 #  include "BLI_offset_indices.hh"
@@ -26,6 +28,11 @@ struct MDeformVert;
 struct Object;
 struct bDeformGroup;
 
+typedef struct DeformGroupUniqueNameData {
+  ID *id;
+  bDeformGroup *dg;
+} DeformGroupUniqueNameData;
+
 bool BKE_object_supports_vertex_groups(const struct Object *ob);
 const struct ListBase *BKE_object_defgroup_list(const struct Object *ob);
 struct ListBase *BKE_object_defgroup_list_mutable(struct Object *ob);
@@ -89,6 +96,7 @@ int *BKE_object_defgroup_flip_map_single(const struct Object *ob,
 int BKE_object_defgroup_flip_index(const struct Object *ob, int index, bool use_default);
 int BKE_object_defgroup_name_index(const struct Object *ob, const char *name);
 void BKE_object_defgroup_unique_name(struct bDeformGroup *dg, struct Object *ob);
+bool BKE_defgroup_unique_name_check(void *arg, const char *name);
 
 struct MDeformWeight *BKE_defvert_find_index(const struct MDeformVert *dv, int defgroup);
 /**

source/blender/blenkernel/intern/attribute.cc

@@ -31,6 +31,7 @@
 #include "BKE_attribute.hh"
 #include "BKE_curves.hh"
 #include "BKE_customdata.h"
+#include "BKE_deform.h"
 #include "BKE_editmesh.h"
 #include "BKE_mesh.hh"
 #include "BKE_pointcloud.h"
@@ -223,11 +224,7 @@ bool BKE_id_attribute_rename(ID *id,
   return true;
 }
 
-struct AttrUniqueData {
-  ID *id;
-};
-
-static bool unique_name_cb(void *arg, const char *name)
+bool BKE_id_attribute_unique_name_check(void *arg, const char *name)
 {
   AttrUniqueData *data = (AttrUniqueData *)arg;
 
@@ -254,6 +251,8 @@ static bool unique_name_cb(void *arg, const char *name)
 
 bool BKE_id_attribute_calc_unique_name(ID *id, const char *name, char *outname)
 {
+  bool success = false;
+
   AttrUniqueData data{id};
   const int name_maxncpy = CustomData_name_maxncpy_calc(name);
 
@@ -261,8 +260,17 @@ bool BKE_id_attribute_calc_unique_name(ID *id, const char *name, char *outname)
    * NOTE: We only call IFACE_() if needed to avoid locale lookup overhead. */
   BLI_strncpy_utf8(outname, (name && name[0]) ? name : IFACE_("Attribute"), name_maxncpy);
 
+  /* Correct name collisions with attributes. */
   const char *defname = ""; /* Dummy argument, never used as `name` is never zero length. */
-  return BLI_uniquename_cb(unique_name_cb, &data, defname, '.', outname, name_maxncpy);
+  success |= BLI_uniquename_cb(
+      BKE_id_attribute_unique_name_check, &data, defname, '.', outname, name_maxncpy);
+
+  /* Also correct name collisions with vertex groups. */
+  DeformGroupUniqueNameData data_dg{id, nullptr};
+  success |= BLI_uniquename_cb(
+      BKE_defgroup_unique_name_check, &data_dg, defname, '.', outname, name_maxncpy);
+
+  return success;
 }
 
 CustomDataLayer *BKE_id_attribute_new(ID *id,
@@ -301,6 +309,11 @@ CustomDataLayer *BKE_id_attribute_new(ID *id,
   attributes->add(uniquename, domain, eCustomDataType(type), AttributeInitDefaultValue());
 
   const int index = CustomData_get_named_layer_index(customdata, type, uniquename);
+  if (index == -1) {
+    BKE_reportf(
+        reports, RPT_WARNING, "Layer '%s' could not be created with a unique name", uniquename);
+  }
+
   return (index == -1) ? nullptr : &(customdata->layers[index]);
 }
 

source/blender/blenkernel/intern/deform.cc

@@ -29,6 +29,7 @@
 
 #include "BLT_translation.h"
 
+#include "BKE_attribute.hh"
 #include "BKE_customdata.h"
 #include "BKE_data_transfer.h"
 #include "BKE_deform.h" /* own include */
@@ -447,6 +448,9 @@ bool BKE_object_supports_vertex_groups(const Object *ob)
 const ListBase *BKE_id_defgroup_list_get(const ID *id)
 {
   switch (GS(id->name)) {
+    case ID_OB: {
+      return BKE_object_defgroup_list((const Object *)id);
+    }
     case ID_ME: {
       const Mesh *me = (const Mesh *)id;
       return &me->vertex_group_names;
@@ -681,9 +685,9 @@ int BKE_object_defgroup_flip_index(const Object *ob, int index, const bool use_d
   return (flip_index == -1 && use_default) ? index : flip_index;
 }
 
-static bool defgroup_find_name_dupe(const char *name, bDeformGroup *dg, Object *ob)
+static bool defgroup_find_name_dupe(const char *name, bDeformGroup *dg, ID *id)
 {
-  const ListBase *defbase = BKE_object_defgroup_list(ob);
+  const ListBase *defbase = BKE_id_defgroup_list_get(id);
   bDeformGroup *curdef;
 
   for (curdef = static_cast<bDeformGroup *>(defbase->first); curdef; curdef = curdef->next) {
@@ -697,21 +701,30 @@ static bool defgroup_find_name_dupe(const char *name, bDeformGroup *dg, Object *
   return false;
 }
 
-struct DeformGroupUniqueNameData {
-  Object *ob;
-  bDeformGroup *dg;
-};
-
-static bool defgroup_unique_check(void *arg, const char *name)
+bool BKE_defgroup_unique_name_check(void *arg, const char *name)
 {
   DeformGroupUniqueNameData *data = static_cast<DeformGroupUniqueNameData *>(arg);
-  return defgroup_find_name_dupe(name, data->dg, data->ob);
+  return defgroup_find_name_dupe(name, data->dg, data->id);
 }
 
 void BKE_object_defgroup_unique_name(bDeformGroup *dg, Object *ob)
 {
-  DeformGroupUniqueNameData data{ob, dg};
-  BLI_uniquename_cb(defgroup_unique_check, &data, DATA_("Group"), '.', dg->name, sizeof(dg->name));
+  /* Correct name name collisions with vertex groups. */
+  DeformGroupUniqueNameData data{&ob->id, dg};
+  BLI_uniquename_cb(
+      BKE_defgroup_unique_name_check, &data, DATA_("Group"), '.', dg->name, sizeof(dg->name));
+
+  /* Also correct name name collisions with (mesh) attributes. */
+  if (ob->type == OB_MESH) {
+    Mesh *me = static_cast<Mesh *>(ob->data);
+    AttrUniqueData data_attr{&me->id};
+    BLI_uniquename_cb(BKE_id_attribute_unique_name_check,
+                      &data_attr,
+                      DATA_("Group"),
+                      '.',
+                      dg->name,
+                      sizeof(dg->name));
+  }
 }
 
 float BKE_defvert_find_weight(const MDeformVert *dvert, const int defgroup)