[Bf-blender-cvs] [ccab410ee73] temp-vert-normals-cleanup: Clarify mesh normal validation

[Hans Goudey]

Commit: ccab410ee7337dbdbc87bf29288a00ecc0dc21aa
Author: Hans Goudey
Date:   Wed Jan 5 14:50:42 2022 -0600
Branches: temp-vert-normals-cleanup
https://developer.blender.org/rBccab410ee7337dbdbc87bf29288a00ecc0dc21aa

Clarify mesh normal validation

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

M	source/blender/blenkernel/intern/mesh_validate.c

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

diff --git a/source/blender/blenkernel/intern/mesh_validate.c b/source/blender/blenkernel/intern/mesh_validate.c
index 1970658e3ae..fb2a92b5797 100644
--- a/source/blender/blenkernel/intern/mesh_validate.c
+++ b/source/blender/blenkernel/intern/mesh_validate.c
@@ -303,7 +303,10 @@ bool BKE_mesh_validate_arrays(Mesh *mesh,
     recalc_flag.edges = do_fixes;
   }
 
-  const float(*vert_normals)[3] = BKE_mesh_vertex_normals_ensure(mesh);
+  const float(*vert_normals)[3] = NULL;
+  if (!BKE_mesh_vertex_normals_are_dirty(mesh)) {
+    vert_normals = BKE_mesh_vertex_normals_ensure(mesh);
+  }
 
   for (i = 0; i < totvert; i++, mv++) {
     bool fix_normal = true;
@@ -319,13 +322,13 @@ bool BKE_mesh_validate_arrays(Mesh *mesh,
         }
       }
 
-      if (vert_normals[i][j] != 0.0f) {
+      if (vert_normals && vert_normals[i][j] != 0.0f) {
         fix_normal = false;
         break;
       }
     }
 
-    if (fix_normal) {
+    if (vert_normals && fix_normal) {
       /* If the vertex normal accumulates to zero or isn't part of a face, the location is used.
        * When the location is also zero, a zero normal warning should not be raised.
        * since this is the expected behavior of normal calculation.