Fix T97518: All buttons with eyedropper highlight if one is hovered

Issue is that the operator acts on the active button, and also uses that in the
poll. So the actually active button would affect the poll of a different
button. For the superimposed icons we need to be able to execute these polls
properly for non-active buttons.

This enables temporarily overriding the active button for lookups via context.
While a bit of a hack it makes sense conceptually.

Reviewed By: Campbell Barton

Maniphest Tasks: T97518

Differential Revision: https://developer.blender.org/D14880

1 files changed, 21 insertions, 4 deletions

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;