From bca56cf2549419751a8f2f73bd920515b980e28b Mon Sep 17 00:00:00 2001
From: Aleksei Nikiforov <darktemplar@basealt.ru>
Date: Tue, 03 Sep 2019 13:07:25 +0300
Subject: [PATCH] Qt xcb: remove false detects of Qt::GroupSwitchModifier

In some cases, if X11 is configured with CapsLock as
keyboard language switch key, and CapsLock is toggled
via Shift+CapsLock key combination,
toggled CapsLock is falsely detected as Qt::GroupSwitchModifier
for subsequent key events.

This change fixes this false detect,
but doesn't fix detection of Qt::GroupSwitchModifier
which is likely still broken.

Fixes: QTBUG-49771
Fixes: QTBUG-95108
Fixes: QTBUG-95289
See also: https://codereview.qt-project.org/c/qt/qtbase/+/371421
See also: https://bugreports.qt.io/browse/QTBUG-95108?focusedCommentId=581870&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-581870
---

diff --git a/src/plugins/platforms/xcb/qxcbkeyboard.cpp b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
index 3caee3f..5e30f25 100644
--- a/src/plugins/platforms/xcb/qxcbkeyboard.cpp
+++ b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
@@ -60,11 +60,11 @@
         ret |= Qt::ShiftModifier;
     if (s & XCB_MOD_MASK_CONTROL)
         ret |= Qt::ControlModifier;
-    if (s & rmod_masks.alt)
+    if (rmod_masks.alt && ((s & rmod_masks.alt) == rmod_masks.alt))
         ret |= Qt::AltModifier;
-    if (s & rmod_masks.meta)
+    if (rmod_masks.meta && ((s & rmod_masks.meta) == rmod_masks.meta))
         ret |= Qt::MetaModifier;
-    if (s & rmod_masks.altgr)
+    if (rmod_masks.altgr && ((s & rmod_masks.altgr) == rmod_masks.altgr))
         ret |= Qt::GroupSwitchModifier;
     return ret;
 }