Wayland: fix GL thread races, reconnect ordering and sizing bugs

- GL swaps on a rendering thread no longer touch frame callbacks or
  presentation feedback. They set a per-surface flag and wake the loop; the
  owner thread arms both at its next flush and commits, so the frame callback
  fires without waiting for the application's next swap.
- Clear the offline flag only after the reconnect rebuild succeeds, and not
  when the connection was lost again during it.
- make_current fails with ENOTCONN for a window without a context. Detaching
  is a no-op when nothing is current or the EGL display is gone.
- Window move, resize, window menu and drag start need a pointer button or
  tablet tip that is still held; otherwise they fail with ESTALE and use that
  press's serial. Popups fail with ESTALE without an input serial and with
  ENOTCONN while the display is lost.
- An oversized device size shrinks to the buffer limits, keeping the aspect
  ratio, instead of closing the window.
- FIXED_SIZE windows pin xdg min and max on every set_size. The 64px minimum
  applies only to compositor-suggested sizes, not to application sizes.
- The keyboard-enter serial becomes the input serial. Clipboard copy with no
  keyboard focus fails with ESTALE.
- Relative-pointer windows relock after a reconnect rebuild.
- errno: EBUSY for an active drag, ENOTSUP for place_under_pointer and for GL
  without EGL, EINVAL for drag carry without a drag.
- Default window title and app ID are "YASL".
- Pointer motion and button events carry unrounded device-pixel positions in
  precise_x/precise_y with precise_position set.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/platform/wayland/internal.h b/src/platform/wayland/internal.h
index ff1b18f..d5b7de1 100644
--- a/src/platform/wayland/internal.h
+++ b/src/platform/wayland/internal.h
@@ -35,6 +35,7 @@
 #include <fcntl.h>
 #include <limits.h>
 #include <poll.h>
+#include <pthread.h>
 #include <time.h>
 #include <linux/input-event-codes.h>
 #include <stdio.h>
@@ -79,6 +80,7 @@ struct wl_conn_output {
 struct pending_press {
     struct wayland_surface *surface;
     struct yasl_private_vector2i pos;
+    struct yasl_private_vector2d precise;
     int button;
     bool release;
 };
@@ -179,6 +181,8 @@ struct seat {
     struct yasl_private_vector2i pointer_pos;
     struct yasl_private_vector2i ptr_left_pos;
     struct yasl_private_vector2i tool_pos;
+    /* Unrounded device-pixel positions behind the rounded ones above. */
+    struct yasl_private_vector2d pointer_precise, ptr_left_precise, tool_precise;
     struct touch_point touch_points[SEAT_TOUCH_POINTS];
     struct press_queue ptr_presses;
     struct press_queue tool_presses;
@@ -212,6 +216,8 @@ struct wayland_display {
     struct yasl_private_display base;
     /* 8-byte pointers & 64-bit masks */
     struct wl_display *wl;
+    /* The thread that opened the display: the only one that arms frame callbacks. */
+    pthread_t owner;
 #if YASL_HAS_EGL
     EGLDisplay egl_display;
     EGLint egl_api;
@@ -363,6 +369,8 @@ struct wayland_surface {
     bool relative;
     bool pointer_locked;
     bool ime_delete_pending;
+    /* Set by a swap on a rendering thread; the owner arms the frame request at its next flush. */
+    atomic_bool frame_deferred;
 };
 
 
@@ -389,6 +397,7 @@ static inline void wl_damage_list(struct wl_surface *s, const struct yasl_privat
 
 void surface_update_opaque_region(struct wayland_surface *w);
 int  surface_init_scaling(struct wayland_surface *w);
+void surface_arm_deferred(struct wayland_surface *w);
 
 uint64_t conn_output_mask(const struct wayland_display *c, const struct wl_output *proxy);
 uint32_t conn_output_scale_120(const struct wayland_display *c, uint64_t outputs);
@@ -425,6 +434,10 @@ void seat_bind(struct wayland_display *c, struct wl_registry *registry,
 bool seat_remove(struct wayland_display *c, uint32_t name);
 void seat_destroy(struct seat *s);
 void seat_note_input(struct seat *s, uint32_t serial);
+/* Serial of the latest press while a pointer button or tablet tip is still down, else 0. */
+uint32_t seat_held_press_serial(const struct seat *s);
+/* Locks the pointer through the seat that last delivered input, or any seat with a pointer. */
+void surface_lock_preferred(struct wayland_surface *w);
 void seat_ensure_text_input(struct seat *s);
 void seat_forget_surface(struct seat *s, struct wayland_surface *w);
 void seat_clipboard_ensure(struct seat *s);