Fix logic error in QString::replace(ch, after, cs)

Coverage analysis showed that an if-branch marked "Q_LIKELY" was never
taken. It turns out the code was incorrect, but behaved correctly.
This patch fixes the logic and adds a unit test.

Pick-to: 5.15
Change-Id: I9b4ba76392b52f07b8e21188496e23f98dba95a9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/auto/corelib/text/qstring/tst_qstring.cpp b/tests/auto/corelib/text/qstring/tst_qstring.cpp
index 47470abd6f..e6d73c6ef1 100644
--- a/tests/auto/corelib/text/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp
@@ -2876,6 +2876,17 @@ void tst_QString::replace_string_extra()
         s.replace( QString("BBB"), smallReplacement );
         QCOMPARE( s, smallReplacement );
     }
+
+    {
+        QString s(QLatin1String("BBB"));
+        QString expected(QLatin1String("BBB"));
+        for (int i = 0; i < 1028; ++i) {
+            s.append("X");
+            expected.append("GXU");
+        }
+        s.replace(QChar('X'), "GXU");
+        QCOMPARE(s, expected);
+    }
 }
 
 void tst_QString::replace_regexp()