From a924f1a629291c6d4bd37f1d062d97c6a57fe18f Mon Sep 17 00:00:00 2001
From: "trop[bot]" <37223003+trop[bot]@users.noreply.github.com>
Date: Fri, 7 Nov 2025 18:41:47 +0100
Subject: [PATCH] fix: CSD window frame tiles properly on Wayland (#48836)

fix: CSD window frame tiles properly on Linux

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Mitchell Cohen <mitch.cohen@me.com>
---
 ...electron_desktop_window_tree_host_linux.cc | 10 ++++++++--
 .../ui/views/client_frame_view_linux.cc       | 20 +++++++++++++------
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/shell/browser/ui/electron_desktop_window_tree_host_linux.cc b/shell/browser/ui/electron_desktop_window_tree_host_linux.cc
index 4502f132c7..ff0fa9051c 100644
--- a/shell/browser/ui/electron_desktop_window_tree_host_linux.cc
+++ b/shell/browser/ui/electron_desktop_window_tree_host_linux.cc
@@ -100,13 +100,19 @@ void ElectronDesktopWindowTreeHostLinux::OnWindowStateChanged(
 void ElectronDesktopWindowTreeHostLinux::OnWindowTiledStateChanged(
     ui::WindowTiledEdges new_tiled_edges) {
   if (auto* const view = native_window_view_->GetClientFrameViewLinux()) {
-    bool maximized = new_tiled_edges.top && new_tiled_edges.left &&
-                     new_tiled_edges.bottom && new_tiled_edges.right;
+    // GNOME on Ubuntu reports all edges as tiled
+    // even if the window is only half-tiled so do not trust individual edge
+    // values.
+    bool maximized = native_window_view_->IsMaximized();
     bool tiled = new_tiled_edges.top || new_tiled_edges.left ||
                  new_tiled_edges.bottom || new_tiled_edges.right;
     view->set_tiled(tiled && !maximized);
   }
   UpdateFrameHints();
+  ScheduleRelayout();
+  if (GetWidget()->non_client_view()) {
+    GetWidget()->non_client_view()->SchedulePaint();
+  }
 }
 
 void ElectronDesktopWindowTreeHostLinux::UpdateWindowState(
diff --git a/shell/browser/ui/views/client_frame_view_linux.cc b/shell/browser/ui/views/client_frame_view_linux.cc
index 316752492b..591fca437f 100644
--- a/shell/browser/ui/views/client_frame_view_linux.cc
+++ b/shell/browser/ui/views/client_frame_view_linux.cc
@@ -40,7 +40,6 @@ namespace {
 
 // These values should be the same as Chromium uses.
 constexpr int kResizeBorder = 10;
-constexpr int kResizeInsideBoundsSize = 5;
 
 ui::NavButtonProvider::ButtonState ButtonStateToNavButtonProviderState(
     views::Button::ButtonState state) {
@@ -151,8 +150,19 @@ gfx::Insets ClientFrameViewLinux::RestoredMirroredFrameBorderInsets() const {
 
 gfx::Insets ClientFrameViewLinux::RestoredFrameBorderInsets() const {
   gfx::Insets insets = GetFrameProvider()->GetFrameThicknessDip();
-  insets.SetToMax(GetInputInsets());
-  return insets;
+  const gfx::Insets input = GetInputInsets();
+
+  auto expand_if_visible = [](int side_thickness, int min_band) {
+    return side_thickness > 0 ? std::max(side_thickness, min_band) : 0;
+  };
+
+  gfx::Insets merged;
+  merged.set_top(expand_if_visible(insets.top(), input.top()));
+  merged.set_left(expand_if_visible(insets.left(), input.left()));
+  merged.set_bottom(expand_if_visible(insets.bottom(), input.bottom()));
+  merged.set_right(expand_if_visible(insets.right(), input.right()));
+
+  return merged;
 }
 
 gfx::Insets ClientFrameViewLinux::GetInputInsets() const {
@@ -197,9 +207,7 @@ void ClientFrameViewLinux::OnWindowButtonOrderingChange() {
 }
 
 int ClientFrameViewLinux::ResizingBorderHitTest(const gfx::Point& point) {
-  return ResizingBorderHitTestImpl(point,
-                                   RestoredMirroredFrameBorderInsets() +
-                                       gfx::Insets(kResizeInsideBoundsSize));
+  return ResizingBorderHitTestImpl(point, RestoredMirroredFrameBorderInsets());
 }
 
 gfx::Rect ClientFrameViewLinux::GetBoundsForClientView() const {