QString: fix an aliasing issue in remove(QString)

Even in Qt 5, remove() can be passed an alias to *this. In Qt 6, with
the advent of substring sharing, this will become even more
pronounced. Use the same fix as was already used in QString::insert().

Pick-to: 5.15
Change-Id: I1a0d3d99fd7dff6e727661646d2cbfdc94df2682
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/auto/corelib/text/qstring/tst_qstring.cpp b/tests/auto/corelib/text/qstring/tst_qstring.cpp
index cefcd4f2e5..38df331cc2 100644
--- a/tests/auto/corelib/text/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/text/qstring/tst_qstring.cpp
@@ -388,6 +388,7 @@ private slots:
     void remove_string();
     void remove_regexp_data();
     void remove_regexp();
+    void remove_extra();
     void swap();
 
     void prepend_qstring()            { prepend_impl<QString>(); }
@@ -3028,6 +3029,15 @@ void tst_QString::remove_regexp()
     }
 }
 
+void tst_QString::remove_extra()
+{
+    {
+        QString s = "The quick brown fox jumps over the lazy dog. "
+                    "The lazy dog jumps over the quick brown fox.";
+        s.remove(s);
+    }
+}
+
 void tst_QString::toNum()
 {
 #if defined (Q_OS_WIN) && defined (Q_CC_MSVC)