Fix T37709: Memory corruption when freeing custom bone shape objects

Summary:
Issue was caused by access to pchan->custom object from channel free
function when freeing all objects from main. Order of objects free
is not defined and such an access might easily end up with access
to freed memory.

We don't need to do user counter stuff when freeing main, so added
an _ex functions with do_id_user flag which is used when freeing main.

We had the same issue with other datablocks, so now it should be
easier to support relevant user counter.

This issue was caused by the fix for T36391, so perhaps that's indeed
high time to do real user counter.

Reviewers: brecht, campbellbarton

Reviewed By: campbellbarton

Maniphest Tasks: T37709

Differential Revision: https://developer.blender.org/D137

1 files changed, 41 insertions, 36 deletions

diff --git a/source/blender/blenkernel/intern/library.c b/source/blender/blenkernel/intern/library.c
index 9b8d34e651d..95f1cce38e3 100644
--- a/source/blender/blenkernel/intern/library.c
+++ b/source/blender/blenkernel/intern/library.c
@@ -867,7 +867,7 @@ void BKE_libblock_free_data(ID *id)
 }
 
 /* used in headerbuttons.c image.c mesh.c screen.c sound.c and library.c */
-void BKE_libblock_free(ListBase *lb, void *idv)
+void BKE_libblock_free_ex(ListBase *lb, void *idv, bool do_id_user)
 {
 	Main *bmain = G.main;  /* should eventually be an arg */
 	ID *id = idv;
@@ -884,7 +884,7 @@ void BKE_libblock_free(ListBase *lb, void *idv)
 			BKE_library_free((Library *)id);
 			break;
 		case ID_OB:
-			BKE_object_free((Object *)id);
+			BKE_object_free_ex((Object *)id, do_id_user);
 			break;
 		case ID_ME:
 			BKE_mesh_free((Mesh *)id, 1);
@@ -987,6 +987,11 @@ void BKE_libblock_free(ListBase *lb, void *idv)
 	MEM_freeN(id);
 }
 
+void BKE_libblock_free(ListBase *lb, void *idv)
+{
+	BKE_libblock_free_ex(lb, idv, true);
+}
+
 void BKE_libblock_free_us(ListBase *lb, void *idv)      /* test users */
 {
 	ID *id = idv;
@@ -1018,44 +1023,44 @@ void free_main(Main *mainvar)
 		
 		while ( (id = lb->first) ) {
 #if 1
-			BKE_libblock_free(lb, id);
+			BKE_libblock_free_ex(lb, id, false);
 #else
 			/* errors freeing ID's can be hard to track down,
 			 * enable this so valgrind will give the line number in its error log */
 			switch (a) {
-				case   0: BKE_libblock_free(lb, id); break;
-				case   1: BKE_libblock_free(lb, id); break;
-				case   2: BKE_libblock_free(lb, id); break;
-				case   3: BKE_libblock_free(lb, id); break;
-				case   4: BKE_libblock_free(lb, id); break;
-				case   5: BKE_libblock_free(lb, id); break;
-				case   6: BKE_libblock_free(lb, id); break;
-				case   7: BKE_libblock_free(lb, id); break;
-				case   8: BKE_libblock_free(lb, id); break;
-				case   9: BKE_libblock_free(lb, id); break;
-				case  10: BKE_libblock_free(lb, id); break;
-				case  11: BKE_libblock_free(lb, id); break;
-				case  12: BKE_libblock_free(lb, id); break;
-				case  13: BKE_libblock_free(lb, id); break;
-				case  14: BKE_libblock_free(lb, id); break;
-				case  15: BKE_libblock_free(lb, id); break;
-				case  16: BKE_libblock_free(lb, id); break;
-				case  17: BKE_libblock_free(lb, id); break;
-				case  18: BKE_libblock_free(lb, id); break;
-				case  19: BKE_libblock_free(lb, id); break;
-				case  20: BKE_libblock_free(lb, id); break;
-				case  21: BKE_libblock_free(lb, id); break;
-				case  22: BKE_libblock_free(lb, id); break;
-				case  23: BKE_libblock_free(lb, id); break;
-				case  24: BKE_libblock_free(lb, id); break;
-				case  25: BKE_libblock_free(lb, id); break;
-				case  26: BKE_libblock_free(lb, id); break;
-				case  27: BKE_libblock_free(lb, id); break;
-				case  28: BKE_libblock_free(lb, id); break;
-				case  29: BKE_libblock_free(lb, id); break;
-				case  30: BKE_libblock_free(lb, id); break;
-				case  31: BKE_libblock_free(lb, id); break;
-				case  32: BKE_libblock_free(lb, id); break;
+				case   0: BKE_libblock_free_ex(lb, id, false); break;
+				case   1: BKE_libblock_free_ex(lb, id, false); break;
+				case   2: BKE_libblock_free_ex(lb, id, false); break;
+				case   3: BKE_libblock_free_ex(lb, id, false); break;
+				case   4: BKE_libblock_free_ex(lb, id, false); break;
+				case   5: BKE_libblock_free_ex(lb, id, false); break;
+				case   6: BKE_libblock_free_ex(lb, id, false); break;
+				case   7: BKE_libblock_free_ex(lb, id, false); break;
+				case   8: BKE_libblock_free_ex(lb, id, false); break;
+				case   9: BKE_libblock_free_ex(lb, id, false); break;
+				case  10: BKE_libblock_free_ex(lb, id, false); break;
+				case  11: BKE_libblock_free_ex(lb, id, false); break;
+				case  12: BKE_libblock_free_ex(lb, id, false); break;
+				case  13: BKE_libblock_free_ex(lb, id, false); break;
+				case  14: BKE_libblock_free_ex(lb, id, false); break;
+				case  15: BKE_libblock_free_ex(lb, id, false); break;
+				case  16: BKE_libblock_free_ex(lb, id, false); break;
+				case  17: BKE_libblock_free_ex(lb, id, false); break;
+				case  18: BKE_libblock_free_ex(lb, id, false); break;
+				case  19: BKE_libblock_free_ex(lb, id, false); break;
+				case  20: BKE_libblock_free_ex(lb, id, false); break;
+				case  21: BKE_libblock_free_ex(lb, id, false); break;
+				case  22: BKE_libblock_free_ex(lb, id, false); break;
+				case  23: BKE_libblock_free_ex(lb, id, false); break;
+				case  24: BKE_libblock_free_ex(lb, id, false); break;
+				case  25: BKE_libblock_free_ex(lb, id, false); break;
+				case  26: BKE_libblock_free_ex(lb, id, false); break;
+				case  27: BKE_libblock_free_ex(lb, id, false); break;
+				case  28: BKE_libblock_free_ex(lb, id, false); break;
+				case  29: BKE_libblock_free_ex(lb, id, false); break;
+				case  30: BKE_libblock_free_ex(lb, id, false); break;
+				case  31: BKE_libblock_free_ex(lb, id, false); break;
+				case  32: BKE_libblock_free_ex(lb, id, false); break;
 				default:
 					BLI_assert(0);
 					break;