Fix window re-rendering when ReInit() called within OnPaint/draw handler

src/gfx.cpp

@@ -80,8 +80,10 @@ static const uint DIRTY_BLOCK_WIDTH    = 64;
 
 extern uint _dirty_block_colour;
 static bool _whole_screen_dirty = false;
+bool _gfx_draw_active = false;
 
 static std::vector<Rect> _dirty_blocks;
+static std::vector<Rect> _pending_dirty_blocks;
 
 /**
  * Applies a certain FillRectMode-operation to a rectangle [left, right] x [top, bottom] on the screen.
@@ -1511,6 +1513,8 @@ void DrawDirtyBlocks()
 	extern void ViewportPrepareVehicleRoute();
 	ViewportPrepareVehicleRoute();
 
+	_gfx_draw_active = true;
+
 	if (_whole_screen_dirty) {
 		RedrawScreenRect(0, 0, _screen.width, _screen.height);
 		Window *w;
@@ -1677,6 +1681,17 @@ void DrawDirtyBlocks()
 	}
 
 	_dirty_blocks.clear();
+	while (!_pending_dirty_blocks.empty()) {
+		for (const Rect &r : _pending_dirty_blocks) {
+			SetDirtyBlocks(r.left, r.top, r.right, r.bottom);
+		}
+		_pending_dirty_blocks.clear();
+		for (const Rect &r : _dirty_blocks) {
+			RedrawScreenRect(r.left, r.top, r.right, r.bottom);
+		}
+		_dirty_blocks.clear();
+	}
+	_gfx_draw_active = false;
 	++_dirty_block_colour;
 
 	extern void ClearViewPortCaches();
@@ -1816,6 +1831,11 @@ void SetDirtyBlocks(int left, int top, int right, int bottom)
 	AddDirtyBlocks(0, left, top, right, bottom);
 }
 
+void SetPendingDirtyBlocks(int left, int top, int right, int bottom)
+{
+	_pending_dirty_blocks.push_back({ left, top, right, bottom });
+}
+
 /**
  * This function mark the whole screen as dirty. This results in repainting
  * the whole screen. Use this with care as this function will break the

src/gfx_func.h

@@ -133,6 +133,7 @@ const char *GetCharAtPosition(const char *str, int x, FontSize start_fontsize =
 
 void DrawDirtyBlocks();
 void SetDirtyBlocks(int left, int top, int right, int bottom);
+void SetPendingDirtyBlocks(int left, int top, int right, int bottom);
 void UnsetDirtyBlocks(int left, int top, int right, int bottom);
 void MarkWholeScreenDirty();
 

src/window.cpp

@@ -974,6 +974,11 @@ void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
 	_cur_dpi = old_dpi;
 }
 
+static void SetWindowDirtyPending(Window *w)
+{
+	SetPendingDirtyBlocks(w->left, w->top, w->left + w->width, w->top + w->height);
+}
+
 /**
  * Mark entire window as dirty (in need of re-paint)
  * @ingroup dirty
@@ -989,7 +994,12 @@ void Window::SetDirty()
  */
 void Window::SetDirtyAsBlocks()
 {
-	SetDirtyBlocks(this->left, this->top, this->left + this->width, this->top + this->height);
+	extern bool _gfx_draw_active;
+	if (_gfx_draw_active) {
+		SetWindowDirtyPending(this);
+	} else {
+		SetDirtyBlocks(this->left, this->top, this->left + this->width, this->top + this->height);
+	}
 }
 
 /**
@@ -2180,7 +2190,12 @@ void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen)
 
 	/* Always call OnResize to make sure everything is initialised correctly if it needs to be. */
 	w->OnResize();
-	w->SetDirty();
+	extern bool _gfx_draw_active;
+	if (_gfx_draw_active) {
+		SetWindowDirtyPending(w);
+	} else {
+		w->SetDirty();
+	}
 }
 
 /**