Fix T57316: material preview icons not updating.

The editors update callback was getting the COW datablock, it should be the
original where the preview icons are stored.

2 files changed, 8 insertions, 22 deletions

diff --git a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
index 18806f389ca..d84f1be4ee0 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
@@ -262,9 +262,15 @@ void flush_editors_id_update(Main *bmain,
 		DEG_DEBUG_PRINTF((::Depsgraph *)graph,
 		                 EVAL, "Accumulated recalc bits for %s: %u\n",
 		                 id_orig->name, (unsigned int)id_cow->recalc);
-		/* Inform editors. */
+
+		/* Inform editors. Only if the datablock is being evaluated a second
+		 * time, to distinguish between user edits and initial evaluation when
+		 * the datablock becomes visible.
+		 *
+		 * TODO: image datablocks do not use COW, so might not be detected
+		 * correctly. */
 		if (deg_copy_on_write_is_expanded(id_cow)) {
-			deg_editors_id_update(update_ctx, id_cow);
+			deg_editors_id_update(update_ctx, id_orig);
 			/* ID may need to get its auto-override operations refreshed. */
 			if (ID_IS_STATIC_OVERRIDE_AUTO(id_orig)) {
 				id_orig->tag |= LIB_TAG_OVERRIDESTATIC_AUTOREFRESH;
diff --git a/source/blender/makesrna/intern/rna_material.c b/source/blender/makesrna/intern/rna_material.c
index 42ec5871109..2d38a99af63 100644
--- a/source/blender/makesrna/intern/rna_material.c
+++ b/source/blender/makesrna/intern/rna_material.c
@@ -114,27 +114,8 @@ static void rna_Material_update_previews(Main *UNUSED(bmain), Scene *UNUSED(scen
 static void rna_MaterialGpencil_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 {
 	Material *ma = ptr->id.data;
-	PreviewImage *preview = ma->preview;
 
 	rna_Material_update(bmain, scene, ptr);
-
-	/* update previews (icon and thumbnail) */
-	if (preview != NULL) {
-		bool changed = false;
-		if ((preview->flag[ICON_SIZE_ICON] & PRV_CHANGED) == 0) {
-			preview->flag[ICON_SIZE_ICON] |= PRV_CHANGED;
-			changed = true;
-		}
-
-		if ((preview->flag[ICON_SIZE_PREVIEW] & PRV_CHANGED) == 0) {
-			preview->flag[ICON_SIZE_PREVIEW] |= PRV_CHANGED;
-			changed = true;
-		}
-
-		if (changed) {
-			WM_main_add_notifier(NC_MATERIAL | ND_SHADING_PREVIEW, ma);
-		}
-	}
 	WM_main_add_notifier(NC_GPENCIL | ND_DATA, ma);
 }
 
@@ -143,7 +124,6 @@ static void rna_MaterialGpencil_nopreview_update(Main *bmain, Scene *scene, Poin
 	Material *ma = ptr->id.data;
 
 	rna_Material_update(bmain, scene, ptr);
-
 	WM_main_add_notifier(NC_GPENCIL | ND_DATA, ma);
 }