[Bf-blender-cvs] [5d1efa9759c] blender-v2.83-release: Fix T93117: Texture paint clone tool crash in certain situation

[Philipp Oeser]

Commit: 5d1efa9759c9050fb3f50102cec5a33836f6d225
Author: Philipp Oeser
Date:   Fri Nov 26 10:00:09 2021 +0100
Branches: blender-v2.83-release
https://developer.blender.org/rB5d1efa9759c9050fb3f50102cec5a33836f6d225

Fix T93117: Texture paint clone tool crash in certain situation

Caused by {rBaf162658e127}, so long standing bug.

When changing clone slots (report involved a quite complicated sequence
of selecting textures and undo -- but I think this could happen in more
situations) code checks for UV of new clone slot.
However, since above commit the slot and the clone slot were mixed up,
so in this case the responsible NULL check (for when no UV is assigned)
wasnt working.
Now correct this (NULL check the clone slot uv -- instead of the paint
slot UV).

note: not sure why low level CustomData functions actually dont do the
name NULL checks themselves (seems like callers are always responsible).

Maniphest Tasks: T93117

Differential Revision: https://developer.blender.org/D13378

===================================================================

M	source/blender/editors/sculpt_paint/paint_image_proj.c

===================================================================

diff --git a/source/blender/editors/sculpt_paint/paint_image_proj.c b/source/blender/editors/sculpt_paint/paint_image_proj.c
index 832f56738ce..558a5db673c 100644
--- a/source/blender/editors/sculpt_paint/paint_image_proj.c
+++ b/source/blender/editors/sculpt_paint/paint_image_proj.c
@@ -4163,8 +4163,9 @@ static bool project_paint_clone_face_skip(ProjPaintState *ps,
 
     if (ps->do_material_slots) {
       if (lc->slot_clone != lc->slot_last_clone) {
-        if (!slot->uvname || !(lc->mloopuv_clone_base = CustomData_get_layer_named(
-                                   &ps->me_eval->ldata, CD_MLOOPUV, lc->slot_clone->uvname))) {
+        if (!lc->slot_clone->uvname ||
+            !(lc->mloopuv_clone_base = CustomData_get_layer_named(
+                  &ps->me_eval->ldata, CD_MLOOPUV, lc->slot_clone->uvname))) {
           lc->mloopuv_clone_base = CustomData_get_layer(&ps->me_eval->ldata, CD_MLOOPUV);
         }
         lc->slot_last_clone = lc->slot_clone;