Constraints: add missing calls to initialize custom space.

Add calls to a few locations that look like they may need to
initialize the Custom Space matrix, i.e. generally any place
that computes target matrices.

Differential Revision: https://developer.blender.org/D9732

source/blender/blenkernel/intern/constraint.c

@@ -6259,6 +6259,9 @@ void BKE_constraint_target_matrix_get(struct Depsgraph *depsgraph,
       }
     }
 
+    /* Initialize the custom space for use in calculating the matrices. */
+    BKE_constraint_custom_object_space_init(cob, con);
+
     /* get targets - we only need the first one though (and there should only be one) */
     cti->get_constraint_targets(con, &targets);
 

source/blender/draw/engines/overlay/overlay_extra.c

@@ -1315,6 +1315,8 @@ static void OVERLAY_relationship_lines(OVERLAY_ExtraCallBuffers *cb,
         if ((curcon->ui_expand_flag & (1 << 0)) && BKE_constraint_targets_get(curcon, &targets)) {
           bConstraintTarget *ct;
 
+          BKE_constraint_custom_object_space_init(cob, curcon);
+
           for (ct = targets.first; ct; ct = ct->next) {
             /* calculate target's matrix */
             if (cti->get_target_matrix) {

source/blender/editors/transform/transform_mode.c

@@ -292,6 +292,9 @@ void constraintTransLim(const TransInfo *t, TransData *td)
           continue;
         }
 
+        /* Initialize the custom space for use in calculating the matrices. */
+        BKE_constraint_custom_object_space_init(&cob, con);
+
         /* get constraint targets if needed */
         BKE_constraint_targets_for_solving_get(t->depsgraph, con, &cob, &targets, ctime);