[gtk/wip/carlosg/im-wayland-serials] WIP: gtk/imwayland: Use serial to control outbound messages

[Carlos Garnacho <carlosg src gnome org>]

commit 4b960f9fd6258d9cee555f7d2c9d0173de39b3ae
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Jan 18 23:31:09 2022 +0100

    WIP: gtk/imwayland: Use serial to control outbound messages
    
    Following the text-input protocol changes at
    https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/115,
    use the serial number to have the client push changes to the
    zwp_text_input_v3 object only after compositor/client states match.
    
    This specifically is more lenient to compositors pushing multiple
    .done events ahead of the client replying to them.
    
    Closes: https://gitlab.gnome.org/GNOME/gtk/-/issues/3641

 gtk/gtkimcontextwayland.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)
---
diff --git a/gtk/gtkimcontextwayland.c b/gtk/gtkimcontextwayland.c
index 8b372d048f..7384b45386 100644
--- a/gtk/gtkimcontextwayland.c
+++ b/gtk/gtkimcontextwayland.c
@@ -48,6 +48,7 @@ struct _GtkIMContextWaylandGlobal
   gboolean focused;
 
   guint serial;
+  guint done_serial;
 };
 
 struct _GtkIMContextWaylandClass
@@ -207,11 +208,11 @@ text_input_commit (void                     *data,
 }
 
 static void
-text_input_commit_apply (GtkIMContextWaylandGlobal *global, gboolean valid)
+text_input_commit_apply (GtkIMContextWaylandGlobal *global)
 {
   GtkIMContextWayland *context;
   context = GTK_IM_CONTEXT_WAYLAND (global->current);
-  if (context->pending_commit && valid)
+  if (context->pending_commit)
     g_signal_emit_by_name (global->current, "commit", context->pending_commit);
   g_free (context->pending_commit);
   context->pending_commit = NULL;
@@ -236,8 +237,7 @@ text_input_delete_surrounding_text (void                     *data,
 }
 
 static void
-text_input_delete_surrounding_text_apply (GtkIMContextWaylandGlobal *global,
-  gboolean valid)
+text_input_delete_surrounding_text_apply (GtkIMContextWaylandGlobal *global)
 {
   GtkIMContextWayland *context;
   gboolean retval;
@@ -248,7 +248,7 @@ text_input_delete_surrounding_text_apply (GtkIMContextWaylandGlobal *global,
 
   len = context->pending_surrounding_delete.after_length
       + context->pending_surrounding_delete.before_length;
-  if (len > 0 && valid)
+  if (len > 0)
     g_signal_emit_by_name (global->current, "delete-surrounding",
                            -context->pending_surrounding_delete.before_length,
                            len, &retval);
@@ -262,16 +262,16 @@ text_input_done (void                     *data,
 {
   GtkIMContextWaylandGlobal *global = data;
   gboolean result;
-  gboolean valid;
-  
+
+  global->done_serial = serial;
+
   if (!global->current)
     return;
 
-  valid = serial == global->serial;
-  text_input_delete_surrounding_text_apply(global, valid);
-  text_input_commit_apply(global, valid);
+  text_input_delete_surrounding_text_apply (global);
+  text_input_commit_apply (global);
   g_signal_emit_by_name (global->current, "retrieve-surrounding", &result);
-  text_input_preedit_apply(global);
+  text_input_preedit_apply (global);
 }
 
 static void
@@ -288,6 +288,8 @@ notify_surrounding_text (GtkIMContextWayland *context)
   global = gtk_im_context_wayland_get_global (context);
   if (global == NULL)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   len = strlen (context->surrounding.text);
   cursor = context->surrounding.cursor_idx;
@@ -362,6 +364,8 @@ notify_cursor_location (GtkIMContextWayland *context)
   global = gtk_im_context_wayland_get_global (context);
   if (global == NULL)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   rect = context->cursor_rect;
   gtk_widget_translate_coordinates (context->widget,
@@ -449,6 +453,8 @@ notify_content_type (GtkIMContextWayland *context)
   global = gtk_im_context_wayland_get_global (context);
   if (global == NULL)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   g_object_get (context,
                 "input-hints", &hints,