Add an session-wise uuid integer to IDs.

"session-wise" here mean while editing a same .blend file. So creating
or opening a new one will reset the uuid counter. This should avoid any
overflow in practice.

Only IDs added to Main database get an uuid, runtime-only ones are not
affected.

This is intended to provide undo with a way to find IDs across several
'memory realms' (undo speedup project).

No behavior change is expected from this commit itself.

Part of T60695.

Differential Revision: https://developer.blender.org/D7007

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index dae6f62319d..2dcacc3dc30 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -77,6 +77,7 @@
 #include "BKE_context.h"
 #include "BKE_global.h"
 #include "BKE_idprop.h"
+#include "BKE_lib_id.h"
 #include "BKE_lib_override.h"
 #include "BKE_main.h"
 #include "BKE_packedFile.h"
@@ -611,6 +612,9 @@ bool WM_file_read(bContext *C, const char *filepath, ReportList *reports)
 
   UI_view2d_zoom_cache_reset();
 
+  /* Reset session-wise ID UUID counter. */
+  BKE_lib_libblock_session_uuid_reset();
+
   /* first try to append data from exotic file formats... */
   /* it throws error box when file doesn't exist and returns -1 */
   /* note; it should set some error message somewhere... (ton) */
@@ -917,6 +921,9 @@ void wm_homefile_read(bContext *C,
     }
   }
 
+  /* Reset session-wise ID UUID counter. */
+  BKE_lib_libblock_session_uuid_reset();
+
   if (!use_factory_settings || (filepath_startup[0] != '\0')) {
     if (BLI_access(filepath_startup, R_OK) == 0) {
       success = BKE_blendfile_read(C,