Fix 32-bit Unicode truncation and QChar assertion crashes#633
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wineee wants to merge 1 commit intolxqt:masterfrom
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Fix 32-bit Unicode truncation and QChar assertion crashes#633wineee wants to merge 1 commit intolxqt:masterfrom
wineee wants to merge 1 commit intolxqt:masterfrom
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This commit addresses crashes caused by Qt 6 enforcing strict range checks (<= 0xFFFF) in the QChar(uint) constructor, as well as fixing internal truncation issues for characters outside the Basic Multilingual Plane (BMP). - Converted TerminalDisplay::charClass to return char32_t instead of QChar, fixing assertions in word extraction algorithms. - Replaced QChar-based unicode checks directly initialized from wchar_t with safe static QChar properties (QChar::category, QChar::isSpace) acting on char32_t values. - Replaced slow and unsafe character width calculations with a fast-path surrogate check (QChar::requiresSurrogates), only allocating QStrings for extended glyphs, avoiding rendering loop performance penalties. - Fixed Character(quint16 _c) constructor inadvertently truncating 32-bit codepoints. - Converted CompactHistoryLine properties to uint* rather than quint16* to prevent scrollback from discarding upper bits of wide characters.
wineee
commented
Apr 17, 2026
| * @param _r A set of rendition flags which specify how this character is to be drawn. | ||
| */ | ||
| inline Character(quint16 _c = ' ', | ||
| inline Character(wchar_t _c = ' ', |
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kconsole switched from quint16 to uint, and qtermwidget was changed to wchat_t, but it seems some parts were missed.
Starting from Qt6, some function parameters of QChar have been changed from uint to char32_t, which is a C++ standard type. I think it might be better to switch wchar_t to char32_t...
wineee
commented
Apr 17, 2026
| bool lineDraw = isLineChar(newLine[x+0]); | ||
| bool doubleWidth = (x+1 == columnsToUpdate) ? false : (newLine[x+1].character == 0); | ||
| int charWidth = fm.horizontalAdvance(QChar(c)); | ||
| int charWidth = QChar::requiresSurrogates(c) ? fm.horizontalAdvance(QString::fromWCharArray(&c, 1)) : fm.horizontalAdvance(QChar(static_cast<ushort>(c))); |
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It's not clear if there is a more efficient approach here, as konsole's logic has changed a bit and didn't use horizontalAdvance.
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This commit addresses crashes caused by Qt 6 enforcing strict range checks (<= 0xFFFF) in the QChar(uint) constructor, as well as fixing internal truncation issues for characters outside the Basic Multilingual Plane (BMP).
fix: #632