Revert "QString::lastIndexOf: fix off-by-one for zero length matches"

This reverts commit 3a273ac47f20e82a1f2f63411b210025ca0f4495.
The revert is needed as QString::lastIndexOf was broken after
the original patch.

Task-number: QTBUG-94215
Change-Id: Ic1c81daa7b5ce8861911210ff34049ed7704ed4a
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 3 insertions, 3 deletions

diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 3c08d970ed..bac6d20c0c 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -4562,13 +4562,13 @@ int QString::lastIndexOf(const QRegularExpression &re, int from, QRegularExpress
         return -1;
     }
 
-    int endpos = (from < 0) ? (size() + from + 1) : (from);
+    int endpos = (from < 0) ? (size() + from + 1) : (from + 1);
     QRegularExpressionMatchIterator iterator = re.globalMatch(*this);
     int lastIndex = -1;
     while (iterator.hasNext()) {
         QRegularExpressionMatch match = iterator.next();
         int 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 49dc23a695..696b8159ac 100644
--- a/tests/auto/corelib/text/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp
@@ -1675,7 +1675,7 @@ 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() && needle.size() > 0) {
+    if (from >= -1 && from < haystack.size()) {
         // unfortunately, QString and QRegExp don't have the same out of bound semantics
         // I think QString is wrong -- See file log for contact information.
         {