Fix T84367: Fix crash when showing invalid/legacy constraints

Exposed by rBeaa44afe703e.

Definition for CONSTRAINT_TYPE_NULL is not totally clear (it is set for
constraints without data, see an old comment from Ton), but for these, a
TypeInfo cannot be fetched.

Avoid processing those constraints in UI code, just do nothing instead.

Maniphest Tasks: T84367

Differential Revision: https://developer.blender.org/D9987

1 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index a035ab86579..e9a6809f170 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -2301,6 +2301,11 @@ static void object_constraint_panel_id(void *md_link, char *r_name)
   bConstraint *con = (bConstraint *)md_link;
   const bConstraintTypeInfo *cti = BKE_constraint_typeinfo_from_type(con->type);
 
+  /* Cannot get TypeInfo for invalid/legacy constraints. */
+  if (cti == NULL) {
+    return;
+  }
+
   strcpy(r_name, CONSTRAINT_TYPE_PANEL_PREFIX);
   strcat(r_name, cti->structName);
 }
@@ -2310,6 +2315,11 @@ static void bone_constraint_panel_id(void *md_link, char *r_name)
   bConstraint *con = (bConstraint *)md_link;
   const bConstraintTypeInfo *cti = BKE_constraint_typeinfo_from_type(con->type);
 
+  /* Cannot get TypeInfo for invalid/legacy constraints. */
+  if (cti == NULL) {
+    return;
+  }
+
   strcpy(r_name, CONSTRAINT_BONE_TYPE_PANEL_PREFIX);
   strcat(r_name, cti->structName);
 }
@@ -2340,6 +2350,10 @@ void uiTemplateConstraints(uiLayout *UNUSED(layout), bContext *C, bool use_bone_
     UI_panels_free_instanced(C, region);
     bConstraint *con = (constraints == NULL) ? NULL : constraints->first;
     for (int i = 0; con; i++, con = con->next) {
+      /* Dont show invalid/legacy constraints. */
+      if (con->type == CONSTRAINT_TYPE_NULL) {
+        continue;
+      }
       /* Dont show temporary constraints (AutoIK and targetless IK constraints). */
       if (con->type == CONSTRAINT_TYPE_KINEMATIC) {
         bKinematicConstraint *data = con->data;
@@ -2369,6 +2383,10 @@ void uiTemplateConstraints(uiLayout *UNUSED(layout), bContext *C, bool use_bone_
     /* Assuming there's only one group of instanced panels, update the custom data pointers. */
     Panel *panel = region->panels.first;
     LISTBASE_FOREACH (bConstraint *, con, constraints) {
+      /* Dont show invalid/legacy constraints. */
+      if (con->type == CONSTRAINT_TYPE_NULL) {
+        continue;
+      }
       /* Dont show temporary constraints (AutoIK and targetless IK constraints). */
       if (con->type == CONSTRAINT_TYPE_KINEMATIC) {
         bKinematicConstraint *data = con->data;