Merge remote-tracking branch 'origin/pr/4492'

1 files changed, 32 insertions, 2 deletions

diff --git a/qutebrowser/keyinput/keyutils.py b/qutebrowser/keyinput/keyutils.py
index 95b270ea2..81e7f2e21 100644
--- a/qutebrowser/keyinput/keyutils.py
+++ b/qutebrowser/keyinput/keyutils.py
@@ -163,6 +163,15 @@ def _is_printable(key):
     return key <= 0xff and key not in [Qt.Key_Space, 0x0]
 
 
+def _is_surrogate(key):
+    """Check if a codepoint is a UTF-16 surrogate.
+
+    UTF-16 surrogates are a reserved range of Unicode from 0xd800
+    to 0xd8ff, used to encode Unicode codepoints above the BMP
+    (Base Multilingual Plane)"""
+    return 0xd800 <= key <= 0xdfff
+
+
 def is_special(key, modifiers):
     """Check whether this key requires special key syntax."""
     _assert_plain_key(key)
@@ -182,6 +191,27 @@ def is_modifier_key(key):
     return key in _MODIFIER_MAP
 
 
+def _remap_unicode(key, text):
+    """Work around QtKeyEvent's bad values for high codepoints.
+
+    QKeyEvent handles higher unicode codepoints poorly (see
+    QTBUG-72776). It uses UTF-16 to handle key events, and for
+    higher codepoints that require UTF-16 surrogates (e.g. emoji
+    and some CJK characters), it sets the keycode to just the
+    upper half of the surrogate, which renders it useless, and
+    breaks UTF-8 encoding, causing crashes. So we detect this
+    case, and reassign the key code to be the full Unicode
+    codepoint, which we can recover from the text() property,
+    wihch has the full character."""
+    if _is_surrogate(key):
+        if len(text) != 1:
+            raise KeyParseError(text, "Key had too many characters!")
+        else:
+            return ord(text[0])
+    else:
+        return key
+
+
 def _check_valid_utf8(s, data):
     """Make sure the given string is valid UTF-8.
 
@@ -317,7 +347,7 @@ class KeyInfo:
 
     @classmethod
     def from_event(cls, e):
-        return cls(e.key(), e.modifiers())
+        return cls(_remap_unicode(e.key(), e.text()), e.modifiers())
 
     def __str__(self):
         """Convert this KeyInfo to a meaningful name.
@@ -525,7 +555,7 @@ class KeySequence:
 
     def append_event(self, ev):
         """Create a new KeySequence object with the given QKeyEvent added."""
-        key = ev.key()
+        key = _remap_unicode(ev.key(), ev.text())
         modifiers = ev.modifiers()
 
         _assert_plain_key(key)