whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QString: fix count(QRegularExpression) 

There is an off by one in the implementation of count(): a match
must be attempted even at the very end of the string, because
a 0-length match can happen there. While at it, improve
the documentation on the counter-intuitive behavior of count(),
which doesn't merely count how many times a regexp matches
into a string using ordinary global matching.

[ChangeLog][QtCore][QString] Fixed a corner case when using
QString::count(QRegularExpression), causing an empty in the
last position not to be accounted for in the returned result.

Change-Id: I064497839a96979abfbac2d0a96546ce160bbc46
Pick-to: 5.15 6.0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
bb10
Giuseppe D'Angelo 2020-12-07 19:03:10 +01:00
parent 92c066b1e5
commit 7c3208c97d
2 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/corelib/text/qstring.cpp
View File

@ -4324,10 +4324,16 @@ bool QString::contains(const QRegularExpression &re, QRegularExpressionMatch *rm
Returns the number of times the regular expression \a re matches
in the string.
This function counts overlapping matches, so in the example
below, there are four instances of "ana" or "ama":
For historical reasons, this function counts overlapping matches,
so in the example below, there are four instances of "ana" or
"ama":
\snippet qstring/main.cpp 95
This behavior is different from simply iterating over the matches
in the string using QRegularExpressionMatchIterator.
\sa QRegularExpression::globalMatch()
*/
qsizetype QString::count(const QRegularExpression &re) const
{
@ -4338,7 +4344,7 @@ qsizetype QString::count(const QRegularExpression &re) const
qsizetype count = 0;
qsizetype index = -1;
qsizetype len = length();
while (index < len - 1) {
while (index <= len - 1) {
QRegularExpressionMatch match = re.match(*this, index + 1);
if (!match.hasMatch())
break;

1
tests/auto/corelib/text/qstring/tst_qstring.cpp
View File

@ -1714,6 +1714,7 @@ void tst_QString::count()
QCOMPARE(a.count("FG",Qt::CaseInsensitive),3);
QCOMPARE(a.count( QString(), Qt::CaseInsensitive), 16);
QCOMPARE(a.count( "", Qt::CaseInsensitive), 16);
QCOMPARE(a.count(QRegularExpression("")), 16);
QCOMPARE(a.count(QRegularExpression("[FG][HI]")), 1);
QCOMPARE(a.count(QRegularExpression("[G][HE]")), 2);
QTest::ignoreMessage(QtWarningMsg, "QString::count: invalid QRegularExpression object");