mutter/mutter-fix-text-input-delete-surrounding.patch

From 27bdf0c577a551254551fdaaf7870c5072707c69 Mon Sep 17 00:00:00 2001
From: Alynx Zhou <alynx.zhou@gmail.com>
Date: Fri, 25 Nov 2022 15:48:01 +0800
Subject: [PATCH 1/2] wayland/text-input: Use byte based offset in
 delete_surrounding_text

ClutterInputFocus/GtkIMContext uses char based offset for
delete_surrounding, however, text_input_v3 uses byte based offset for
it. Currently only GTK with mutter can work correctly via text_input_v3
because they both forget to convert between char based offset and byte
based offset.

This commit fixes it in mutter by saving committed surrounding text in
MetaWaylandTextInput and converting char based offset to byte based
offset with the UTF-8 encoded surrounding text.

Fixes <https://gitlab.gnome.org/GNOME/mutter/-/issues/2146>.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2712>
---
 src/wayland/meta-wayland-text-input.c | 55 +++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 8 deletions(-)

diff --git a/src/wayland/meta-wayland-text-input.c b/src/wayland/meta-wayland-text-input.c
index b1ceb1a6bb5..2e694dc1eb8 100644
--- a/src/wayland/meta-wayland-text-input.c
+++ b/src/wayland/meta-wayland-text-input.c
@@ -58,6 +58,20 @@ struct _MetaWaylandTextInput
 
   GHashTable *resource_serials;
 
+  /* This saves the uncommitted middle state of surrounding text from client
+   * between `set_surrounding_text` and `commit`, will be cleared after
+   * committed.
+   */
+  struct
+  {
+    char *text;
+    uint32_t cursor;
+    uint32_t anchor;
+  } pending_surrounding;
+
+  /* This is the actual committed surrounding text after `commit`, we need this
+   * to convert between char based offset and byte based offset.
+   */
   struct
   {
     char *text;
@@ -216,14 +230,32 @@ meta_wayland_text_input_focus_delete_surrounding (ClutterInputFocus *focus,
                                                   guint              len)
 {
   MetaWaylandTextInput *text_input;
+  const char *start, *end;
+  const char *before, *after;
+  const char *cursor;
   uint32_t before_length;
   uint32_t after_length;
   struct wl_resource *resource;
 
+  /* offset and len are counted by UTF-8 chars, but text_input_v3's lengths are
+   * counted by bytes, so we convert UTF-8 char offsets to pointers here, this
+   * needs the surrounding text
+   */
   text_input = META_WAYLAND_TEXT_INPUT_FOCUS (focus)->text_input;
-  before_length = ABS (MIN (offset, 0));
-  after_length = MAX (0, offset + len);
-  g_warn_if_fail (ABS (offset) <= len);
+  offset = MIN (offset, 0);
+
+  start = text_input->surrounding.text;
+  end = start + strlen (text_input->surrounding.text);
+  cursor = start + text_input->surrounding.cursor;
+
+  before = g_utf8_offset_to_pointer (cursor, offset);
+  g_assert (before >= start);
+
+  after = g_utf8_offset_to_pointer (cursor, offset + len);
+  g_assert (after <= end);
+
+  before_length = cursor - before;
+  after_length = after - cursor;
 
   wl_resource_for_each (resource, &text_input->focus_resource_list)
     {
@@ -468,10 +500,10 @@ text_input_set_surrounding_text (struct wl_client   *client,
   if (!client_matches_focus (text_input, client))
     return;
 
-  g_free (text_input->surrounding.text);
-  text_input->surrounding.text = g_strdup (text);
-  text_input->surrounding.cursor = cursor;
-  text_input->surrounding.anchor = anchor;
+  g_free (text_input->pending_surrounding.text);
+  text_input->pending_surrounding.text = g_strdup (text);
+  text_input->pending_surrounding.cursor = cursor;
+  text_input->pending_surrounding.anchor = anchor;
   text_input->pending_state |= META_WAYLAND_PENDING_STATE_SURROUNDING_TEXT;
 }
 
@@ -591,7 +623,7 @@ text_input_set_cursor_rectangle (struct wl_client   *client,
 static void
 meta_wayland_text_input_reset (MetaWaylandTextInput *text_input)
 {
-  g_clear_pointer (&text_input->surrounding.text, g_free);
+  g_clear_pointer (&text_input->pending_surrounding.text, g_free);
   text_input->content_type_hint = ZWP_TEXT_INPUT_V3_CONTENT_HINT_NONE;
   text_input->content_type_purpose = ZWP_TEXT_INPUT_V3_CONTENT_PURPOSE_NORMAL;
   text_input->text_change_cause = ZWP_TEXT_INPUT_V3_CHANGE_CAUSE_INPUT_METHOD;
@@ -651,6 +683,12 @@ text_input_commit_state (struct wl_client   *client,
 
   if (text_input->pending_state & META_WAYLAND_PENDING_STATE_SURROUNDING_TEXT)
     {
+      /* Save the surrounding text for `delete_surrounding_text`. */
+      g_free (text_input->surrounding.text);
+      text_input->surrounding.text = g_steal_pointer (&text_input->pending_surrounding.text);
+      text_input->surrounding.cursor = text_input->pending_surrounding.cursor;
+      text_input->surrounding.anchor = text_input->pending_surrounding.anchor;
+      /* Pass the surrounding text to Clutter to handle it with input method. */
       clutter_input_focus_set_surrounding (text_input->input_focus,
                                            text_input->surrounding.text,
                                            text_input->surrounding.cursor,
@@ -720,6 +758,7 @@ meta_wayland_text_input_destroy (MetaWaylandTextInput *text_input)
   g_object_unref (text_input->input_focus);
   g_hash_table_destroy (text_input->resource_serials);
   g_clear_pointer (&text_input->preedit.string, g_free);
+  g_clear_pointer (&text_input->pending_surrounding.text, g_free);
   g_clear_pointer (&text_input->surrounding.text, g_free);
   g_free (text_input);
 }
-- 
GitLab


From 33088d59db742cf802977a9d8ec8b4ea3ca79ea0 Mon Sep 17 00:00:00 2001
From: Alynx Zhou <alynx.zhou@gmail.com>
Date: Mon, 23 Oct 2023 14:32:21 +0800
Subject: [PATCH 2/2] wayland/text-input: Pass char based offset to
 ClutterInputFocus

Wayland's text-input-v3 uses byte based offset for cursor and anchor of
surrounding text, but Clutter needs char based offset here. This commit
converts byte based offset to char based offset before passing them to
ClutterInputFocus.

Fixes <https://gitlab.gnome.org/GNOME/mutter/-/issues/3102>.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2712>
---
 src/wayland/meta-wayland-text-input.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/wayland/meta-wayland-text-input.c b/src/wayland/meta-wayland-text-input.c
index 2e694dc1eb8..c8f50847a88 100644
--- a/src/wayland/meta-wayland-text-input.c
+++ b/src/wayland/meta-wayland-text-input.c
@@ -122,12 +122,18 @@ static void
 meta_wayland_text_input_focus_request_surrounding (ClutterInputFocus *focus)
 {
   MetaWaylandTextInput *text_input;
+  long cursor, anchor;
 
+  /* Clutter uses char offsets but text-input-v3 uses byte offsets. */
   text_input = META_WAYLAND_TEXT_INPUT_FOCUS (focus)->text_input;
+  cursor = g_utf8_strlen (text_input->surrounding.text,
+                          text_input->surrounding.cursor);
+  anchor = g_utf8_strlen (text_input->surrounding.text,
+                          text_input->surrounding.anchor);
   clutter_input_focus_set_surrounding (focus,
-				       text_input->surrounding.text,
-				       text_input->surrounding.cursor,
-                                       text_input->surrounding.anchor);
+                                       text_input->surrounding.text,
+                                       cursor,
+                                       anchor);
 }
 
 static uint32_t
@@ -683,16 +689,24 @@ text_input_commit_state (struct wl_client   *client,
 
   if (text_input->pending_state & META_WAYLAND_PENDING_STATE_SURROUNDING_TEXT)
     {
+      long cursor, anchor;
+
       /* Save the surrounding text for `delete_surrounding_text`. */
       g_free (text_input->surrounding.text);
       text_input->surrounding.text = g_steal_pointer (&text_input->pending_surrounding.text);
       text_input->surrounding.cursor = text_input->pending_surrounding.cursor;
       text_input->surrounding.anchor = text_input->pending_surrounding.anchor;
+
       /* Pass the surrounding text to Clutter to handle it with input method. */
+      /* Clutter uses char offsets but text-input-v3 uses byte offsets. */
+      cursor = g_utf8_strlen (text_input->surrounding.text,
+                              text_input->surrounding.cursor);
+      anchor = g_utf8_strlen (text_input->surrounding.text,
+                              text_input->surrounding.anchor);
       clutter_input_focus_set_surrounding (text_input->input_focus,
                                            text_input->surrounding.text,
-                                           text_input->surrounding.cursor,
-                                           text_input->surrounding.anchor);
+                                           cursor,
+                                           anchor);
     }
 
   if (text_input->pending_state & META_WAYLAND_PENDING_STATE_INPUT_RECT)
-- 
GitLab