1 files changed, 46 insertions, 12 deletions

diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index c22eb097761..5a5b501e21e 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -1873,14 +1873,22 @@ void uiTemplateModifiers(uiLayout *UNUSED(layout), bContext *C)
     ModifierData *md = modifiers->first;
     for (int i = 0; md; i++, md = md->next) {
       const ModifierTypeInfo *mti = BKE_modifier_get_info(md->type);
-      if (mti->panelRegister) {
-        char panel_idname[MAX_NAME];
-        modifier_panel_id(md, panel_idname);
+      if (mti->panelRegister == NULL) {
+        continue;
+      }
 
-        Panel *new_panel = UI_panel_add_instanced(sa, region, &region->panels, panel_idname, i);
-        if (new_panel != NULL) {
-          UI_panel_set_expand_from_list_data(C, new_panel);
-        }
+      char panel_idname[MAX_NAME];
+      modifier_panel_id(md, panel_idname);
+
+      /* Create custom data RNA pointer. */
+      PointerRNA *md_ptr = MEM_mallocN(sizeof(PointerRNA), "panel customdata");
+      RNA_pointer_create(&ob->id, &RNA_Modifier, md, md_ptr);
+
+      Panel *new_panel = UI_panel_add_instanced(
+          sa, region, &region->panels, panel_idname, i, md_ptr);
+
+      if (new_panel != NULL) {
+        UI_panel_set_expand_from_list_data(C, new_panel);
       }
     }
   }
@@ -1890,6 +1898,27 @@ void uiTemplateModifiers(uiLayout *UNUSED(layout), bContext *C)
       if ((panel->type != NULL) && (panel->type->flag & PNL_INSTANCED))
         UI_panel_set_expand_from_list_data(C, panel);
     }
+
+    /* Assuming there's only one group of instanced panels, update the custom data pointers. */
+    Panel *panel = region->panels.first;
+    LISTBASE_FOREACH (ModifierData *, md, modifiers) {
+      const ModifierTypeInfo *mti = BKE_modifier_get_info(md->type);
+      if (mti->panelRegister == NULL) {
+        continue;
+      }
+
+      /* Move to the next instanced panel corresponding to the next modifier. */
+      while ((panel->type == NULL) || !(panel->type->flag & PNL_INSTANCED)) {
+        panel = panel->next;
+        BLI_assert(panel != NULL); /* There shouldn't be fewer panels than modifiers with UIs. */
+      }
+
+      PointerRNA *md_ptr = MEM_mallocN(sizeof(PointerRNA), "panel customdata");
+      RNA_pointer_create(&ob->id, &RNA_Modifier, md, md_ptr);
+      UI_panel_custom_data_set(panel, md_ptr);
+
+      panel = panel->next;
+    }
   }
 }
 
@@ -2026,9 +2055,11 @@ void uiTemplateConstraints(uiLayout *UNUSED(layout), bContext *C, bool use_bone_
       char panel_idname[MAX_NAME];
       panel_id_func(con, panel_idname);
 
-      Panel *new_panel = UI_panel_add_instanced(sa, region, &region->panels, panel_idname, i);
+      Panel *new_panel = UI_panel_add_instanced(
+          sa, region, &region->panels, panel_idname, i, NULL);
       if (new_panel) {
-        /* Set the list panel functionality function pointers since we don't do it with python. */
+        /* Set the list panel functionality function pointers since we don't do it with
+         * python. */
         new_panel->type->set_list_data_expand_flag = set_constraint_expand_flag;
         new_panel->type->get_list_data_expand_flag = get_constraint_expand_flag;
         new_panel->type->reorder = constraint_reorder;
@@ -2082,7 +2113,8 @@ void uiTemplateGpencilModifiers(uiLayout *UNUSED(layout), bContext *C)
         char panel_idname[MAX_NAME];
         gpencil_modifier_panel_id(md, panel_idname);
 
-        Panel *new_panel = UI_panel_add_instanced(sa, region, &region->panels, panel_idname, i);
+        Panel *new_panel = UI_panel_add_instanced(
+            sa, region, &region->panels, panel_idname, i, NULL);
         if (new_panel != NULL) {
           UI_panel_set_expand_from_list_data(C, new_panel);
         }
@@ -2107,7 +2139,8 @@ void uiTemplateGpencilModifiers(uiLayout *UNUSED(layout), bContext *C)
 /* -------------------------------------------------------------------- */
 /** \name ShaderFx Template
  *
- *  Template for building the panel layout for the active object's grease pencil shader effects.
+ *  Template for building the panel layout for the active object's grease pencil shader
+ * effects.
  * \{ */
 
 /**
@@ -2138,7 +2171,8 @@ void uiTemplateShaderFx(uiLayout *UNUSED(layout), bContext *C)
       char panel_idname[MAX_NAME];
       shaderfx_panel_id(fx, panel_idname);
 
-      Panel *new_panel = UI_panel_add_instanced(sa, region, &region->panels, panel_idname, i);
+      Panel *new_panel = UI_panel_add_instanced(
+          sa, region, &region->panels, panel_idname, i, NULL);
       if (new_panel != NULL) {
         UI_panel_set_expand_from_list_data(C, new_panel);
       }