Fix duplicate brushes from recent startup files

Default versioning caused duplicates when the startup was re-saved.

See c305759762

source/blender/blenkernel/BKE_blender_version.h

@@ -28,7 +28,7 @@
  * and keep comment above the defines.
  * Use STRINGIFY() rather than defining with quotes */
 #define BLENDER_VERSION         280
-#define BLENDER_SUBVERSION      42
+#define BLENDER_SUBVERSION      43
 /* Several breakages with 280, e.g. collections vs layers */
 #define BLENDER_MINVERSION      280
 #define BLENDER_MINSUBVERSION   0

source/blender/blenkernel/BKE_library.h

@@ -195,6 +195,9 @@ void BKE_main_id_clear_newpoins(struct Main *bmain);
 
 void BKE_main_lib_objects_recalc_all(struct Main *bmain);
 
+/* Only for repairing files via versioning, avoid for general use. */
+void BKE_main_id_repair_duplicate_names_listbase(struct ListBase *lb);
+
 #define MAX_ID_FULL_NAME (64 + 64 + 3 + 1)  /* 64 is MAX_ID_NAME - 2 */
 #define MAX_ID_FULL_NAME_UI (MAX_ID_FULL_NAME + 3)  /* Adds 'keycode' two letters at begining. */
 void BKE_id_full_name_get(char name[MAX_ID_FULL_NAME], const struct ID *id);

source/blender/blenkernel/intern/library.c

@@ -999,6 +999,37 @@ void BKE_main_id_flag_all(Main *bmain, const int flag, const bool value)
 	}
 }
 
+void BKE_main_id_repair_duplicate_names_listbase(ListBase *lb)
+{
+	int lb_len = 0;
+	for (ID *id = lb->first; id; id = id->next) {
+		if (id->lib == NULL) {
+			lb_len += 1;
+		}
+	}
+	if (lb_len <= 1) {
+		return;
+	}
+
+	/* Fill an array because renaming sorts. */
+	ID **id_array = MEM_mallocN(sizeof(*id_array) * lb_len, __func__);
+	GSet *gset = BLI_gset_str_new_ex(__func__, lb_len);
+	int i = 0;
+	for (ID *id = lb->first; id; id = id->next) {
+		if (id->lib == NULL) {
+			id_array[i] = id;
+			i++;
+		}
+	}
+	for (i = 0; i < lb_len; i++) {
+		if (!BLI_gset_add(gset, id_array[i]->name + 2)) {
+			new_id(lb, id_array[i], NULL);
+		}
+	}
+	BLI_gset_free(gset, NULL);
+	MEM_freeN(id_array);
+}
+
 void BKE_main_lib_objects_recalc_all(Main *bmain)
 {
 	Object *ob;

source/blender/blenloader/intern/versioning_280.c

@@ -2783,6 +2783,11 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 		}
 	}
 
+	if (!MAIN_VERSION_ATLEAST(bmain, 280, 43)) {
+		ListBase *lb = which_libbase(bmain, ID_BR);
+		BKE_main_id_repair_duplicate_names_listbase(lb);
+	}
+
 	{
 		/* Versioning code until next subversion bump goes here. */
 	}