4 files changed, 54 insertions, 21 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 9f4d6815287..1b61e87b140 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -184,26 +184,26 @@ enum {
 
 /** #uiBut.flag general state flags. */
 enum {
-  /* WARNING: the first 7 flags are internal (see #UI_SELECT definition). */
-  UI_BUT_ICON_SUBMENU = 1 << 7,
-  UI_BUT_ICON_PREVIEW = 1 << 8,
+  /* WARNING: the first 8 flags are internal (see #UI_SELECT definition). */
+  UI_BUT_ICON_SUBMENU = 1 << 8,
+  UI_BUT_ICON_PREVIEW = 1 << 9,
 
-  UI_BUT_NODE_LINK = 1 << 9,
-  UI_BUT_NODE_ACTIVE = 1 << 10,
-  UI_BUT_DRAG_LOCK = 1 << 11,
+  UI_BUT_NODE_LINK = 1 << 10,
+  UI_BUT_NODE_ACTIVE = 1 << 11,
+  UI_BUT_DRAG_LOCK = 1 << 12,
   /** Grayed out and un-editable. */
-  UI_BUT_DISABLED = 1 << 12,
+  UI_BUT_DISABLED = 1 << 13,
 
-  UI_BUT_ANIMATED = 1 << 13,
-  UI_BUT_ANIMATED_KEY = 1 << 14,
-  UI_BUT_DRIVEN = 1 << 15,
-  UI_BUT_REDALERT = 1 << 16,
+  UI_BUT_ANIMATED = 1 << 14,
+  UI_BUT_ANIMATED_KEY = 1 << 15,
+  UI_BUT_DRIVEN = 1 << 16,
+  UI_BUT_REDALERT = 1 << 17,
   /** Grayed out but still editable. */
-  UI_BUT_INACTIVE = 1 << 17,
-  UI_BUT_LAST_ACTIVE = 1 << 18,
-  UI_BUT_UNDO = 1 << 19,
-  UI_BUT_IMMEDIATE = 1 << 20,
-  UI_BUT_NO_UTF8 = 1 << 21,
+  UI_BUT_INACTIVE = 1 << 18,
+  UI_BUT_LAST_ACTIVE = 1 << 19,
+  UI_BUT_UNDO = 1 << 20,
+  UI_BUT_IMMEDIATE = 1 << 21,
+  UI_BUT_NO_UTF8 = 1 << 22,
 
   /** For popups, pressing return activates this button, overriding the highlighted button.
    * For non-popups this is just used as a display hint for the user to let them
diff --git a/source/blender/editors/interface/interface.cc b/source/blender/editors/interface/interface.cc
index b7098c26bcd..480044118f1 100644
--- a/source/blender/editors/interface/interface.cc
+++ b/source/blender/editors/interface/interface.cc
@@ -1861,15 +1861,32 @@ bool ui_but_context_poll_operator_ex(bContext *C,
                                      const wmOperatorCallParams *optype_params)
 {
   bool result;
+  int old_but_flag = 0;
 
-  if (but && but->context) {
-    CTX_store_set(C, but->context);
+  if (but) {
+    old_but_flag = but->flag;
+
+    /* Temporarily make this button override the active one, in case the poll acts on the active
+     * button. */
+    const_cast<uiBut *>(but)->flag |= UI_BUT_ACTIVE_OVERRIDE;
+
+    if (but->context) {
+      CTX_store_set(C, but->context);
+    }
   }
 
   result = WM_operator_poll_context(C, optype_params->optype, optype_params->opcontext);
 
-  if (but && but->context) {
-    CTX_store_set(C, nullptr);
+  if (but) {
+    BLI_assert_msg((but->flag & ~UI_BUT_ACTIVE_OVERRIDE) ==
+                       (old_but_flag & ~UI_BUT_ACTIVE_OVERRIDE),
+                   "Operator polls shouldn't change button flags");
+
+    const_cast<uiBut *>(but)->flag = old_but_flag;
+
+    if (but->context) {
+      CTX_store_set(C, nullptr);
+    }
   }
 
   return result;
diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index 26b9b82d67f..9d30ad992c9 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -8714,13 +8714,23 @@ static uiBut *ui_context_button_active(const ARegion *region, bool (*but_check_c
     /* find active button */
     LISTBASE_FOREACH (uiBlock *, block, &region->uiblocks) {
       LISTBASE_FOREACH (uiBut *, but, &block->buttons) {
+        if (but->flag & UI_BUT_ACTIVE_OVERRIDE) {
+          activebut = but;
+          break;
+        }
         if (but->active) {
           activebut = but;
+          break;
         }
-        else if (!activebut && (but->flag & UI_BUT_LAST_ACTIVE)) {
+        if (but->flag & UI_BUT_LAST_ACTIVE) {
           activebut = but;
+          break;
         }
       }
+
+      if (activebut) {
+        break;
+      }
     }
 
     if (activebut && (but_check_cb == NULL || but_check_cb(activebut))) {
diff --git a/source/blender/editors/interface/interface_intern.h b/source/blender/editors/interface/interface_intern.h
index b1ca0fa4e92..1c79d3218fb 100644
--- a/source/blender/editors/interface/interface_intern.h
+++ b/source/blender/editors/interface/interface_intern.h
@@ -74,6 +74,12 @@ enum {
   UI_SELECT_DRAW = (1 << 5),
   /** Property search filter is active and the button does not match. */
   UI_SEARCH_FILTER_NO_MATCH = (1 << 6),
+
+  /** Temporarily override the active button for lookups in context, regions, etc. (everything
+   * using #ui_context_button_active()). For example, so that operators normally acting on the
+   * active button can be polled on non-active buttons to (e.g. for disabling). */
+  UI_BUT_ACTIVE_OVERRIDE = (1 << 7),
+
   /* WARNING: rest of #uiBut.flag in UI_interface.h */
 };