From be83ff65c424cff1036e7da19d6175826d9f7ed9 Mon Sep 17 00:00:00 2001 From: Giuseppe D'Angelo Date: Mon, 7 Dec 2020 23:42:33 +0100 Subject: [PATCH] QString::lastIndexOf: fix off-by-one for zero length matches Otherwise, it would report that lastIndexOf of an empty pattern in an empty string doesn't exist. Next commit adds extensive autotests; for now, disable a broken autotest (which already features a comment about why it's broken). Change-Id: I9a0e5c0142007f81f5cf93e356c8bd82f00066f7 Pick-to: 5.15 6.0 Reviewed-by: Thiago Macieira --- src/corelib/text/qstring.cpp | 4 ++-- tests/auto/corelib/text/qstring/tst_qstring.cpp | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp index 02501e00f4..92eed93251 100644 --- a/src/corelib/text/qstring.cpp +++ b/src/corelib/text/qstring.cpp @@ -4273,13 +4273,13 @@ qsizetype QString::lastIndexOf(const QRegularExpression &re, qsizetype from, QRe return -1; } - qsizetype endpos = (from < 0) ? (size() + from + 1) : (from + 1); + qsizetype endpos = (from < 0) ? (size() + from + 1) : (from); QRegularExpressionMatchIterator iterator = re.globalMatch(*this); qsizetype lastIndex = -1; while (iterator.hasNext()) { QRegularExpressionMatch match = iterator.next(); qsizetype start = match.capturedStart(); - if (start < endpos) { + if (start <= endpos) { lastIndex = start; if (rmatch) *rmatch = std::move(match); diff --git a/tests/auto/corelib/text/qstring/tst_qstring.cpp b/tests/auto/corelib/text/qstring/tst_qstring.cpp index 7c965129f0..4d2c4a755b 100644 --- a/tests/auto/corelib/text/qstring/tst_qstring.cpp +++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp @@ -1645,7 +1645,7 @@ void tst_QString::lastIndexOf() QCOMPARE(haystack.lastIndexOf(needle.toLatin1(), from, cs), expected); QCOMPARE(haystack.lastIndexOf(needle.toLatin1().data(), from, cs), expected); - if (from >= -1 && from < haystack.size()) { + if (from >= -1 && from < haystack.size() && needle.size() > 0) { // unfortunately, QString and QRegularExpression don't have the same out of bound semantics // I think QString is wrong -- See file log for contact information. {