# HG changeset patch
# User Peter Nelson <peter1138@openttd.org>
# Date 2024-02-14 17:23:03
# Node ID 67d8065b03e1aeb107475e854fb98fbc0358c356
# Parent  d984b313db3ed975d81163c1ecbcdaaa322149fb

Codechange: Update window's widget lookup map when switching displayed plane.

diff --git a/src/widget.cpp b/src/widget.cpp
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1268,8 +1268,13 @@ void NWidgetStacked::AssignSizePosition(
 
 void NWidgetStacked::FillWidgetLookup(WidgetLookup &widget_lookup)
 {
+	/* We need to update widget_lookup later. */
+	this->widget_lookup = &widget_lookup;
+
 	if (this->index >= 0) widget_lookup[this->index] = this;
 	NWidgetContainer::FillWidgetLookup(widget_lookup);
+	/* In case widget IDs are repeated, make sure Window::GetWidget works on displayed widgets. */
+	if (static_cast<size_t>(this->shown_plane) < this->children.size()) this->children[shown_plane]->FillWidgetLookup(widget_lookup);
 }
 
 void NWidgetStacked::Draw(const Window *w)
@@ -1300,6 +1305,8 @@ bool NWidgetStacked::SetDisplayedPlane(i
 {
 	if (this->shown_plane == plane) return false;
 	this->shown_plane = plane;
+	/* In case widget IDs are repeated, make sure Window::GetWidget works on displayed widgets. */
+	if (static_cast<size_t>(this->shown_plane) < this->children.size()) this->children[shown_plane]->FillWidgetLookup(*this->widget_lookup);
 	return true;
 }
 
diff --git a/src/widget_type.h b/src/widget_type.h
--- a/src/widget_type.h
+++ b/src/widget_type.h
@@ -497,6 +497,8 @@ public:
 
 	int shown_plane; ///< Plane being displayed (for #NWID_SELECTION only).
 	const WidgetID index; ///< If non-negative, index in the #Window::widget_lookup.
+private:
+	WidgetLookup *widget_lookup; ///< Window's widget lookup, updated in SetDisplayedPlane().
 };
 
 /** Nested widget container flags, */