Persistent resize dialog when scrollbar is present

[gpanders]

Issue Description

When the scrollbar is visible, the resize dialog constantly reappears (see video).

Screencast.from.2025-12-05.12-16-24.webm

Disabling the scroll bar (e.g. clearing the screen, going to the alt screen, or setting scrollbar = never) makes the dialog go away.

Expected Behavior

There should not be a resize dialog when the window is not being resized.

Actual Behavior

The resize dialog appears when the window is not resized and persistently reappears.

Reproduction Steps

1. Open Ghostty
2. Create enough scrollback to make the scrollbar appear
3. Observe the resize dialog

Ghostty Logs

No response

Ghostty Version

The commit hash is stripped for some reason, but this is using the latest tip release as of this writing (08c9661).

Ghostty 1.3.0-dev+0000000

Version
  - version: 1.3.0-dev+0000000
  - channel: tip
Build Config
  - Zig version   : 0.15.2
  - build mode    : .ReleaseFast
  - app runtime   : .gtk
  - font engine   : .fontconfig_freetype
  - renderer      : renderer.generic.Renderer(renderer.OpenGL)
  - libxev        : io_uring
  - kernel version: 6.14.0-1015-oem
  - desktop env   : gnome
  - GTK version   :
    build         : 4.14.5
    runtime       : 4.14.5
  - libadwaita    : enabled
    build         : 1.5.0
    runtime       : 1.5.0
  - libX11        : enabled
  - libwayland    : enabled

OS Version Information

Ubuntu 24.04.3

(Linux only) Display Server

Wayland

(Linux only) Desktop Environment/Window Manager

GNOME 46.0

Minimal Ghostty Configuration

# Reproduces with default configuration

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[rhodes-b]

I've not seen this problem on sway both in tiling or floating mode, I also tried client side decor nothing there either
on commit 09f7e38b45ba9ad325c587f4e8acd66b8de8e9d5

I also just rebuilt the latest commit 08c9661683edc1e9e63d8e6abd469a68faaee575 and dont see the issue

[alexkuz]

This bug occurs for me when org.(gnome|cinnamon).desktop.interface.gtk-overlay-scrollbars is set to false (it seems from the screencast that @gpanders has similar setting). This fix suggested by Copilot helped:

--- a/src/apprt/gtk/class/surface.zig
+++ b/src/apprt/gtk/class/surface.zig
@@ -3138,11 +3138,15 @@ pub const Surface = extern struct {

         // Store our cached size
         const priv = self.private();
-        priv.size = .{
+        const new_size: apprt.SurfaceSize = .{
             .width = @intCast(width),
             .height = @intCast(height),
         };

+        // Check if size actually changed to avoid feedback loops with scrollbars
+        const size_changed = priv.size.width != new_size.width or priv.size.height != new_size.height;
+        priv.size = new_size;
+
         // If our surface is realize, we send callbacks.
         if (priv.core_surface) |surface| {
             // We also update the content scale because there is no signal for
@@ -3151,12 +3155,16 @@ pub const Surface = extern struct {
                 log.warn("error in content scale callback err={}", .{err});
             };

-            surface.sizeCallback(priv.size) catch |err| {
-                log.warn("error in size callback err={}", .{err});
-            };
+            // Only call sizeCallback if the size actually changed to prevent
+            // feedback loops when scrollbars are shown/hidden
+            if (size_changed) {
+                surface.sizeCallback(priv.size) catch |err| {
+                    log.warn("error in size callback err={}", .{err});
+                };

-            // Setup our resize overlay if configured
-            self.resizeOverlaySchedule();
+                // Setup our resize overlay if configured
+                self.resizeOverlaySchedule();
+            }

             return;
         }

[gpanders]

This bug occurs for me when org.(gnome|cinnamon).desktop.interface.gtk-overlay-scrollbars is set to false (it seems from the screencast that @gpanders has similar setting).

I don't have this option set either way, as far as I know.