unittest for fast string operator+ not allowing unwanted combinations

Change-Id: I5891efcec7db373407a661636108fd979839db52

sal/inc/rtl/stringconcat.hxx

@@ -260,6 +260,23 @@ typename internal::Enable< OUStringConcat< T1, T2 >, ToStringHelper< T1 >::allow
     return OUStringConcat< T1, T2 >( left, right );
     }
 
+#ifdef RTL_STRING_UNITTEST_CONCAT
+// Special overload to catch the remaining invalid combinations. The helper struct must
+// be used to make this operator+ overload a worse choice than all the existing overloads above.
+struct StringConcatInvalid
+    {
+    template< typename T >
+    StringConcatInvalid( const T& ) {}
+    };
+template< typename T >
+inline
+int operator+( const StringConcatInvalid&, const T& )
+    {
+    rtl_string_unittest_invalid_concat = true;
+    return 0; // doesn't matter
+    }
+#endif
+
 } // namespace
 
 #endif

sal/qa/rtl/strings/test_ostring_concat.cxx

@@ -7,12 +7,18 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+// activate support for detecting errors instead of getting compile errors
+#define RTL_STRING_UNITTEST_CONCAT
+bool rtl_string_unittest_invalid_concat = false;
+
 #include <sal/types.h>
 #include <cppunit/TestFixture.h>
 #include <cppunit/extensions/HelperMacros.h>
 
 #include <rtl/string.hxx>
 #include <rtl/strbuf.hxx>
+#include <rtl/ustring.hxx>
+#include <rtl/ustrbuf.hxx>
 
 #include <typeinfo>
 
@@ -36,11 +42,13 @@ private:
     void checkConcat();
     void checkEnsureCapacity();
     void checkAppend();
+    void checkInvalid();
 
 CPPUNIT_TEST_SUITE(StringConcat);
 CPPUNIT_TEST(checkConcat);
 CPPUNIT_TEST(checkEnsureCapacity);
 CPPUNIT_TEST(checkAppend);
+CPPUNIT_TEST(checkInvalid);
 CPPUNIT_TEST_SUITE_END();
 };
 
@@ -75,6 +83,8 @@ void test::ostring::StringConcat::checkConcat()
     TYPES_ASSERT_EQUAL(( typeid( OStringConcat< OString, const char* > )), typeid( OString( "foo" ) + d3 ));
     CPPUNIT_ASSERT_EQUAL( OString( "fooabc" ), OString( OString( "foo" ) + d4 ));
     TYPES_ASSERT_EQUAL(( typeid( OStringConcat< OString, char* > )), typeid( OString( "foo" ) + d4 ));
+    CPPUNIT_ASSERT_EQUAL( OString( "foobar" ), OString( OStringBuffer( "foo" ) + OString( "bar" )));
+    TYPES_ASSERT_EQUAL(( typeid( OStringConcat< OStringBuffer, OString > )), typeid( OStringBuffer( "foo" ) + OString( "bar" )));
 }
 #undef typeid
 
@@ -126,6 +136,27 @@ void test::ostring::StringConcat::checkAppend()
     CPPUNIT_ASSERT_EQUAL( OString( "foobarbaz" ), buf.makeStringAndClear());
 }
 
+#define INVALID_CONCAT( expression ) \
+    ( \
+    rtl_string_unittest_invalid_concat = false, \
+    ( void ) OString( expression ), \
+    rtl_string_unittest_invalid_concat )
+
+void test::ostring::StringConcat::checkInvalid()
+{
+#ifdef RTL_FAST_STRING
+    CPPUNIT_ASSERT( !INVALID_CONCAT( OString() + OString()));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUString( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUStringBuffer( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUStringLiteral( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + 1 ));
+    rtl_String* rs = NULL;
+    rtl_uString* rus = NULL;
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "b" ) + rs ));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "b" ) + rus ));
+#endif
+}
+
 }} // namespace
 
 CPPUNIT_TEST_SUITE_REGISTRATION(test::ostring::StringConcat);

sal/qa/rtl/strings/test_oustring_concat.cxx

@@ -7,12 +7,18 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+// activate support for detecting errors instead of getting compile errors
+#define RTL_STRING_UNITTEST_CONCAT
+extern bool rtl_string_unittest_invalid_concat;
+
 #include <sal/types.h>
 #include <cppunit/TestFixture.h>
 #include <cppunit/extensions/HelperMacros.h>
 
 #include <rtl/ustring.hxx>
 #include <rtl/ustrbuf.hxx>
+#include <rtl/string.hxx>
+#include <rtl/strbuf.hxx>
 
 #include <typeinfo>
 
@@ -36,11 +42,13 @@ private:
     void checkConcat();
     void checkEnsureCapacity();
     void checkAppend();
+    void checkInvalid();
 
 CPPUNIT_TEST_SUITE(StringConcat);
 CPPUNIT_TEST(checkConcat);
 CPPUNIT_TEST(checkEnsureCapacity);
 CPPUNIT_TEST(checkAppend);
+CPPUNIT_TEST(checkInvalid);
 CPPUNIT_TEST_SUITE_END();
 };
 
@@ -64,6 +72,8 @@ void test::oustring::StringConcat::checkConcat()
     const char d1[] = "xyz";
     CPPUNIT_ASSERT_EQUAL( OUString( "fooxyz" ), OUString( OUString( "foo" ) + d1 ));
     TYPES_ASSERT_EQUAL(( typeid( OUStringConcat< OUString, const char[ 4 ] > )), typeid( OUString( "foo" ) + d1 ));
+    CPPUNIT_ASSERT_EQUAL( OUString( "foobar" ), OUString( OUStringBuffer( "foo" ) + OUString( "bar" )));
+    TYPES_ASSERT_EQUAL(( typeid( OUStringConcat< OUStringBuffer, OUString > )), typeid( OUStringBuffer( "foo" ) + OUString( "bar" )));
 }
 
 void test::oustring::StringConcat::checkEnsureCapacity()
@@ -118,6 +128,32 @@ void test::oustring::StringConcat::checkAppend()
     CPPUNIT_ASSERT_EQUAL( OUString( "foobarbaz" ), buf.makeStringAndClear());
 }
 
+#define INVALID_CONCAT( expression ) \
+    ( \
+    rtl_string_unittest_invalid_concat = false, \
+    ( void ) OUString( expression ), \
+    rtl_string_unittest_invalid_concat )
+
+void test::oustring::StringConcat::checkInvalid()
+{
+#ifdef RTL_FAST_STRING
+    CPPUNIT_ASSERT( !INVALID_CONCAT( OUString() + OUString()));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + OString( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + OStringBuffer( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + (const char*) "b" ));
+    char d[] = "b";
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + d ));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + (char*)d ));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + OStringLiteral( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + 1 ));
+    rtl_String* rs = NULL;
+    rtl_uString* rus = NULL;
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "b" ) + rs ));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "b" ) + rus ));
+#endif
+
+}
+
 }} // namespace
 
 CPPUNIT_TEST_SUITE_REGISTRATION(test::oustring::StringConcat);