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authorRainer Keller <Rainer.Keller@qt.io>2019-08-27 14:44:48 +0200
committerJukka Jokiniva <jukka.jokiniva@qt.io>2019-08-31 08:29:31 +0000
commitaf6ac444c97ed2dc234f93fe457440c9da5482ea (patch)
treeccab66846b2a462dba57e0acad394933dcf937de
parent97465b1540ebd095225679b5dd400b2d4d54e678 (diff)
Fix crash when text contains too many directional charsv5.13.15.13.1
In case a text to be layouted contains more than 128 directional characters it causes the application to crash The function initScriptAnalysisAndIsolatePairs() collects information of RTL/LTR chaaracters into vector "isolatePairs". The size of the vector is capped to 128. Later the function generateDirectionalRuns() iterates the text again and tries to access items from the previously capped vector above the upper bound. Task-number: QTBUG-77819 Change-Id: Ibb7bf12c12b1db22f43ff46236518da3fdeed26a Reviewed-by: Simon Hausmann <simon.hausmann@qt.io> (cherry picked from commit 1232205e32464d90e871f39eb1e14fcf9b78a163) Reviewed-by: Jukka Jokiniva <jukka.jokiniva@qt.io> Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
-rw-r--r--src/gui/text/qtextengine.cpp15
-rw-r--r--tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp17
2 files changed, 24 insertions, 8 deletions
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 2da13289bf..a7834587b1 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -399,6 +399,7 @@ struct QBidiAlgorithm {
analysis[i].bidiDirection = (level & 1) ? QChar::DirR : QChar::DirL;
runHasContent = true;
lastRunWithContent = -1;
+ ++isolatePairPosition;
}
int runBeforeIsolate = runs.size();
ushort newLevel = isRtl ? ((stack.top().level + 1) | 1) : ((stack.top().level + 2) & ~1);
@@ -440,21 +441,19 @@ struct QBidiAlgorithm {
doEmbed(true, true, false);
break;
case QChar::DirLRI:
- Q_ASSERT(isolatePairs.at(isolatePairPosition).start == i);
doEmbed(false, false, true);
- ++isolatePairPosition;
break;
case QChar::DirRLI:
- Q_ASSERT(isolatePairs.at(isolatePairPosition).start == i);
doEmbed(true, false, true);
- ++isolatePairPosition;
break;
case QChar::DirFSI: {
- const auto &pair = isolatePairs.at(isolatePairPosition);
- Q_ASSERT(pair.start == i);
- bool isRtl = QStringView(text + pair.start + 1, pair.end - pair.start - 1).isRightToLeft();
+ bool isRtl = false;
+ if (isolatePairPosition < isolatePairs.size()) {
+ const auto &pair = isolatePairs.at(isolatePairPosition);
+ Q_ASSERT(pair.start == i);
+ isRtl = QStringView(text + pair.start + 1, pair.end - pair.start - 1).isRightToLeft();
+ }
doEmbed(isRtl, false, true);
- ++isolatePairPosition;
break;
}
diff --git a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
index 9c477589f9..f0a32c2ed4 100644
--- a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
+++ b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
@@ -138,6 +138,7 @@ private slots:
void noModificationOfInputString();
void superscriptCrash_qtbug53911();
void showLineAndParagraphSeparatorsCrash();
+ void tooManyDirectionalCharctersCrash_qtbug77819();
private:
QFont testFont;
@@ -2309,5 +2310,21 @@ void tst_QTextLayout::nbspWithFormat()
QCOMPARE(layout.lineAt(1).textLength(), s2.length() + 1 + s3.length());
}
+void tst_QTextLayout::tooManyDirectionalCharctersCrash_qtbug77819()
+{
+ QString data;
+ data += QString::fromUtf8("\xe2\x81\xa8"); // U+2068 FSI character
+ data += QString::fromUtf8("\xe2\x81\xa7"); // U+2067 RLI character
+
+ // duplicating the text
+ for (int i = 0; i < 10; i++)
+ data += data;
+
+ // Nothing to test. It must not crash in beginLayout().
+ QTextLayout tl(data);
+ tl.beginLayout();
+ tl.endLayout();
+}
+
QTEST_MAIN(tst_QTextLayout)
#include "tst_qtextlayout.moc"