x11, ime: Fix keys decoding when GTK_IM_MODULE=xim

As of crrev.com/c/1789603, GdkEventKey::state is not being set correctly when
translating ui::KeyEvent into GdkEvents. Such field should be equivalent to
XKeyEvent::state, which contains, besides modifiers state bits, keyboard group
information. This causes regressions such as crbug.com/1021732, oddly
specifically when GTK_IM_MODULE env variable is set to 'xim'.

This CL fixes it by including 'group' value into GdkEventKey::state composed
value, as was already done in GtkEventLoopX11.

Bug: 1021732
Change-Id: I2d166ab9f88fc46fd5150f0f2d224aa85a22f9a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1902438Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Nick Yamane <nickdiego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#713976}

chrome/browser/ui/libgtkui/gtk_event_loop_x11.cc

@@ -11,30 +11,12 @@
 #include <gtk/gtk.h>
 
 #include "base/memory/singleton.h"
+#include "chrome/browser/ui/libgtkui/gtk_util.h"
 #include "ui/events/platform/x11/x11_event_source.h"
 #include "ui/gfx/x/x11_types.h"
 
 namespace libgtkui {
 
-namespace {
-
-// Xkb Events store group attribute into XKeyEvent::state bit field, along with
-// other state-related info, while GdkEventKey objects have separate fields for
-// that purpose, they are ::state and ::group. This function is responsible for
-// recomposing them into a single bit field value when translating GdkEventKey
-// into XKeyEvent. This is similar to XkbBuildCoreState(), but assumes state is
-// an uint rather than an uchar.
-//
-// More details:
-// https://gitlab.freedesktop.org/xorg/proto/xorgproto/blob/master/include/X11/extensions/XKB.h#L372
-int BuildXkbStateFromGdkEvent(const GdkEventKey& keyev) {
-  DCHECK_EQ(0u, XkbGroupForCoreState(keyev.state));
-  DCHECK(XkbIsLegalGroup(keyev.group));
-  return keyev.state | ((keyev.group & 0x3) << 13);
-}
-
-}  // namespace
-
 // static
 GtkEventLoopX11* GtkEventLoopX11::GetInstance() {
   return base::Singleton<GtkEventLoopX11>::get();
@@ -88,9 +70,10 @@ void GtkEventLoopX11::ProcessGdkEventKey(const GdkEventKey& gdk_event_key) {
   x_event.xkey.window = GDK_WINDOW_XID(gdk_event_key.window);
   x_event.xkey.root = DefaultRootWindow(x_event.xkey.display);
   x_event.xkey.time = gdk_event_key.time;
-  x_event.xkey.state = BuildXkbStateFromGdkEvent(gdk_event_key);
   x_event.xkey.keycode = gdk_event_key.hardware_keycode;
   x_event.xkey.same_screen = true;
+  x_event.xkey.state =
+      BuildXkbStateFromGdkEvent(gdk_event_key.state, gdk_event_key.group);
 
   // We want to process the gtk event; mapped to an X11 event immediately
   // otherwise if we put it back on the queue we may get items out of order.

chrome/browser/ui/libgtkui/gtk_util.cc

@@ -607,6 +607,11 @@ GdkDisplay* GetGdkDisplay() {
   return display;
 }
 
+int BuildXkbStateFromGdkEvent(unsigned int state, unsigned char group) {
+  DCHECK_EQ(0u, ((state >> 13) & 0x3));
+  return state | ((group & 0x3) << 13);
+}
+
 GdkEvent* GdkEventFromKeyEvent(const ui::KeyEvent& key_event) {
   GdkEventType event_type =
       key_event.type() == ui::ET_KEY_PRESSED ? GDK_KEY_PRESS : GDK_KEY_RELEASE;
@@ -632,7 +637,7 @@ GdkEvent* GdkEventFromKeyEvent(const ui::KeyEvent& key_event) {
   gdk_event->key.time = event_time.InMilliseconds();
   gdk_event->key.hardware_keycode = hw_code;
   gdk_event->key.keyval = keyval;
-  gdk_event->key.state = state;
+  gdk_event->key.state = BuildXkbStateFromGdkEvent(state, group);
   gdk_event->key.group = group;
   gdk_event->key.send_event = key_event.flags() & ui::EF_FINAL;
   gdk_event->key.is_modifier = state & GDK_MODIFIER_MASK;

chrome/browser/ui/libgtkui/gtk_util.h

@@ -177,6 +177,17 @@ std::string GetGtkSettingsStringProperty(GtkSettings* settings,
 // Get current GdkDisplay instance
 GdkDisplay* GetGdkDisplay();
 
+// Xkb Events store group attribute into XKeyEvent::state bit field, along with
+// other state-related info, while GdkEventKey objects have separate fields for
+// that purpose, they are ::state and ::group. This function is responsible for
+// recomposing them into a single bit field value when translating GdkEventKey
+// into XKeyEvent. This is similar to XkbBuildCoreState(), but assumes state is
+// an uint rather than an uchar.
+//
+// More details:
+// https://gitlab.freedesktop.org/xorg/proto/xorgproto/blob/master/include/X11/extensions/XKB.h#L372
+int BuildXkbStateFromGdkEvent(unsigned int state, unsigned char group);
+
 // Translates |key_event| into a GdkEvent. GdkEvent::key::window is the only
 // field not set by this function, callers must set it, as the way for
 // retrieving it may vary depending on the event being processed. E.g: for IME