Let a new window pick its own size instead of forcing a guessed placeholder

Root-caused "windows spawn small and square, not remembering placement or
size": new_managed_window hardcoded a fresh toplevel's geometry to 800x632
before the client had said anything about its own preferred size, and
sync_geometry forced that guess onto the client's very first
xdg_toplevel::configure unconditionally. Per xdg-shell, size: None on that
first configure is how every mainstream compositor lets a client pick its
own natural size instead; this one never did, so every app converged on
the same placeholder rectangle regardless of what it would have chosen.

Window::size_is_provisional marks a size that really was just the guess
(not a remembered geometry, a rule's explicit geometry action, or a
maximize/phone-mode fill, none of which are guesses). sync_geometry sends
size: None for such a window's first configure; a new adopt_provisional_size,
called from the commit handler, adopts the client's own real first size
into Window::geometry the moment it commits one, clamping only position so
a bigger-than-guessed window can't hang off its monitor's edge.

Live-verified in a nested compositor: a zenity dialog now renders at its
own compact natural size instead of being stretched to the old guess.

1 files changed, 45 insertions, 0 deletions

diff --git a/crates/core/src/manager/tests.rs b/crates/core/src/manager/tests.rs
index 860af89..f703f25 100644
--- a/crates/core/src/manager/tests.rs
+++ b/crates/core/src/manager/tests.rs
@@ -26,6 +26,51 @@
     }
 
     #[test]
+    fn a_smart_placed_window_is_marked_size_provisional() {
+        let mut wm = wm_with_monitor();
+        let id = wm.alloc_window_id();
+        let w = Window::new(id, "first");
+        wm.add_window(w);
+        // No remembered geometry, no rule, not maximized - the size that
+        // just got smart-placed is nothing but `Window::new`'s own default
+        // guess, so a backend should be free to let the client override it.
+        assert!(wm.window(id).unwrap().size_is_provisional);
+    }
+
+    #[test]
+    fn a_remembered_geometry_is_never_provisional() {
+        let mut wm = wm_with_monitor();
+        wm.set_remembered_geometry("some-app".to_string(), (100, 100, 900, 700));
+        let id = wm.alloc_window_id();
+        let mut w = Window::new(id, "second");
+        w.app_id = "some-app".to_string();
+        wm.add_window(w);
+        let win = wm.window(id).unwrap();
+        assert_eq!((win.geometry.width, win.geometry.height), (900, 700));
+        assert!(!win.size_is_provisional, "a deliberately remembered size must never be second-guessed by the client's own default");
+    }
+
+    #[test]
+    fn a_rules_explicit_geometry_is_never_provisional() {
+        let mut wm = wm_with_monitor();
+        wm.rules.push(WindowRule { matcher: WindowMatch { class: Some("ruled-app".to_string()), ..Default::default() }, actions: WindowRuleActions { geometry: Some(Rect::new(10, 10, 500, 400)), ..Default::default() } });
+        let id = wm.alloc_window_id();
+        let mut w = Window::new(id, "third");
+        w.app_id = "ruled-app".to_string();
+        wm.add_window(w);
+        assert!(!wm.window(id).unwrap().size_is_provisional, "a rule's own explicit geometry is a deliberate choice, not a guess");
+    }
+
+    #[test]
+    fn phone_mode_maximize_is_never_provisional() {
+        let mut wm = wm_with_monitor();
+        wm.phone_mode = true;
+        let id = wm.alloc_window_id();
+        wm.add_window(Window::new(id, "fourth"));
+        assert!(!wm.window(id).unwrap().size_is_provisional, "a deliberate full-monitor fill is not a guess needing a client override");
+    }
+
+    #[test]
     fn add_window_picks_up_the_configured_default_decoration_mode() {
         let mut wm = wm_with_monitor();
         wm.theme.default_decorated = false;