From 8afef45d4e92ea66f35c35102302c97d1632043c Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Sun, 25 Feb 2024 08:35:57 +0000
Subject: [PATCH] Fix d3c673e: Don't defer OnResize() after ReInit() (#12174)

Some windows resize themselves during painting and issue ReInit(). In this case deferred OnResize() causes a visible glitch as the event is handled on the next redraw.
---
 src/window.cpp    | 14 +++++++++-----
 src/window_func.h |  2 +-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/window.cpp b/src/window.cpp
index 2151be5f49..314bc9a72c 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -984,7 +984,7 @@ void Window::ReInit(int rx, int ry, bool reposition)
 		this->FindWindowPlacementAndResize(this->window_desc->GetDefaultWidth(), this->window_desc->GetDefaultHeight());
 	}
 
-	ResizeWindow(this, dx, dy);
+	ResizeWindow(this, dx, dy, true, false);
 	/* ResizeWindow() does this->SetDirty() already, no need to do it again here. */
 }
 
@@ -1447,8 +1447,8 @@ void Window::FindWindowPlacementAndResize(int def_width, int def_height)
 		ResizeWindow(this, enlarge_x, enlarge_y);
 		/* ResizeWindow() calls this->OnResize(). */
 	} else {
-		/* Schedule OnResize; that way the scrollbars and matrices get initialized. */
-		this->ScheduleResize();
+		/* Always call OnResize; that way the scrollbars and matrices get initialized. */
+		this->OnResize();
 	}
 
 	int nx = this->left;
@@ -2024,7 +2024,7 @@ static void EnsureVisibleCaption(Window *w, int nx, int ny)
  * @param delta_y Delta y-size of changed window
  * @param clamp_to_screen Whether to make sure the whole window stays visible
  */
-void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen)
+void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen, bool schedule_resize)
 {
 	if (delta_x != 0 || delta_y != 0) {
 		if (clamp_to_screen) {
@@ -2051,7 +2051,11 @@ void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen)
 	EnsureVisibleCaption(w, w->left, w->top);
 
 	/* Schedule OnResize to make sure everything is initialised correctly if it needs to be. */
-	w->ScheduleResize();
+	if (schedule_resize) {
+		w->ScheduleResize();
+	} else {
+		w->OnResize();
+	}
 	w->SetDirty();
 }
 
diff --git a/src/window_func.h b/src/window_func.h
index da798aa4e9..8bc5aba228 100644
--- a/src/window_func.h
+++ b/src/window_func.h
@@ -26,7 +26,7 @@ Window *FindWindowById(WindowClass cls, T number)
 	return FindWindowById(cls, number.base());
 }
 
-void ResizeWindow(Window *w, int x, int y, bool clamp_to_screen = true);
+void ResizeWindow(Window *w, int x, int y, bool clamp_to_screen = true, bool schedule_resize = true);
 int PositionMainToolbar(Window *w);
 int PositionStatusbar(Window *w);
 int PositionNewsMessage(Window *w);