fix issue qith Qt6.3

Author: sunderme

src/qcodeedit/lib/document/qdocumentsearch.cpp

@@ -678,7 +678,7 @@ int QDocumentSearch::next(bool backward, bool all, bool again, bool allowWrapAro
 		const QDocumentLine& l = m_cursor.line();
 
 		int coloffset = 0;
-		QString s = l.text();
+        s = l.text();
 
 		if ( bounded ) {
 			// update boundaries as scope is changed when changing text

src/qcodeedit/lib/document/qdocumentsearch.h

@@ -106,6 +106,7 @@ class QCE_EXPORT QDocumentSearch: public QObject
 
 		Options m_option;
 		QString m_string;
+        QString s; // keep string alive so that corresponding match may refer it, seems to be changed in Qt5.3
         QRegularExpression m_regularExpression;
         QRegularExpressionMatch m_match;