diff options
Diffstat (limited to 'src/corelib/tools/qchar.cpp')
| -rw-r--r-- | src/corelib/tools/qchar.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/corelib/tools/qchar.cpp b/src/corelib/tools/qchar.cpp index e5d7c82d29..017c0f232e 100644 --- a/src/corelib/tools/qchar.cpp +++ b/src/corelib/tools/qchar.cpp @@ -1546,7 +1546,7 @@ static void composeHelper(QString *str, QChar::UnicodeVersion version, int from) { QString &s = *str; - if (s.length() - from < 2) + if (from < 0 || s.length() - from < 2) return; // the loop can partly ignore high Unicode as all ligatures are in the BMP @@ -1565,12 +1565,13 @@ static void composeHelper(QString *str, QChar::UnicodeVersion version, int from) const QUnicodeTables::Properties *p = qGetProp(uc); if (p->unicodeVersion == QChar::Unicode_Unassigned || p->unicodeVersion > version) { starter = -1; // to prevent starter == pos - 1 - lastCombining = 0; + lastCombining = 255; // to prevent combining > lastCombining ++pos; continue; } int combining = p->combiningClass; if (starter == pos - 1 || combining > lastCombining) { + Q_ASSERT(starter >= from); // allowed to form ligature with S QChar ligature = ligatureHelper(s.at(starter).unicode(), uc); if (ligature.unicode()) { |