PyAPI: Fix memory leak of parameters used for python 'draw_callbacks'

When closing the blender, while the callbacks are removed, the
reference count of the object used as `customdata` is not decremented.

This commit adds two functions that correctly release the
python `draw_callbacks` before releasing all `draw_callbacks`.

Differential Revision: https://developer.blender.org/D10478

1 files changed, 16 insertions, 0 deletions

diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 297575e8dff..bab8359472f 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -2056,6 +2056,22 @@ bool WM_paint_cursor_end(wmPaintCursor *handle)
   return false;
 }
 
+void WM_paint_cursor_remove_by_type(wmWindowManager *wm, void *draw_fn, void (*free)(void *))
+{
+  wmPaintCursor *pc = wm->paintcursors.first;
+  while (pc) {
+    wmPaintCursor *pc_next = pc->next;
+    if (pc->draw == draw_fn) {
+      if (free) {
+        free(pc->customdata);
+      }
+      BLI_remlink(&wm->paintcursors, pc);
+      MEM_freeN(pc);
+    }
+    pc = pc_next;
+  }
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */