add title() expression test row

Author: jef-n

tests/src/core/testqgsexpression.cpp

@@ -263,6 +263,7 @@ class TestQgsExpression: public QObject
       QTest::newRow( "rpad truncate" ) << "rpad('Hello', 4, 'x')" << false << QVariant( "Hell" );
       QTest::newRow( "lpad" ) << "lpad('Hello', 10, 'x')" << false << QVariant( "Helloxxxxx" );
       QTest::newRow( "lpad truncate" ) << "rpad('Hello', 4, 'x')" << false << QVariant( "Hell" );
+      QTest::newRow( "title" ) << "title(' HeLlO   WORLD ')" << false << QVariant( " Hello   World " );
 
       // implicit conversions
       QTest::newRow( "implicit int->text" ) << "length(123)" << false << QVariant( 3 );