[gtk/wip/carlosg/im-wayland-backports-3.24: 1/3] gtk/imwayland: Use serial to control outbound messages

[Carlos Garnacho <carlosg src gnome org>]

commit 802a748e5bd4688cd6b6a251fb6f331bd74cf6a5
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Jan 18 23:31:09 2022 +0100

    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.
    
    (cherry-picked from commit f108f053d4c84dcdedce005a3491cbd503092185)
    
    Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/4853

 modules/input/imwayland.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)
---
diff --git a/modules/input/imwayland.c b/modules/input/imwayland.c
index 9a12b21f6b..91d27ca407 100644
--- a/modules/input/imwayland.c
+++ b/modules/input/imwayland.c
@@ -47,6 +47,7 @@ struct _GtkIMContextWaylandGlobal
   gboolean focused;
 
   guint serial;
+  guint done_serial;
 };
 
 struct _GtkIMContextWaylandClass
@@ -205,11 +206,11 @@ 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;
@@ -234,8 +235,7 @@ 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;
@@ -246,7 +246,7 @@ 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);
@@ -260,16 +260,16 @@ 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
@@ -286,6 +286,8 @@ notify_surrounding_text (GtkIMContextWayland *context)
     return;
   if (!context->enabled || !context->surrounding.text)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   len = strlen (context->surrounding.text);
   cursor = context->surrounding.cursor_idx;
@@ -361,6 +363,8 @@ notify_cursor_location (GtkIMContextWayland *context)
     return;
   if (!context->enabled || !context->window)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   rect = context->cursor_rect;
   gdk_window_get_root_coords (context->window, rect.x, rect.y,
@@ -443,6 +447,8 @@ notify_content_type (GtkIMContextWayland *context)
 
   if (!context->enabled)
     return;
+  if (global->done_serial != global->serial)
+    return;
 
   g_object_get (context,
                 "input-hints", &hints,