OUString construction from OUStringLiteral1 must not be overruled by...

...Except[Const]CharArrayDetector, under RTL_STRING_UNITTEST

Change-Id: Ib185fb8406c4afcff1c854a2b74dae02a0ee2b3f
Reviewed-on: https://gerrit.libreoffice.org/28444Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

include/rtl/stringutils.hxx

@@ -200,6 +200,18 @@ template< int N >
 struct ExceptConstCharArrayDetector< const char[ N ] >
 {
 };
+#if defined LIBO_INTERNAL_ONLY
+template<char C> struct ExceptConstCharArrayDetector<
+#if defined __GNUC__ && __GNUC__ == 4 && __GNUC_MINOR__ <= 8 \
+        && !defined __clang__
+    OUStringLiteral1_<C> const
+#else
+    OUStringLiteral1<C>
+#endif
+    >
+{};
+#endif
+
 // this one is used to rule out only const char[N]
 // (const will be brought in by 'const T&' in the function call)
 // msvc needs const char[N] here (not sure whether gcc or msvc
@@ -217,9 +229,8 @@ template< int N >
 struct ExceptCharArrayDetector< const char[ N ] >
 {
 };
-#if defined LIBO_INTERNAL_ONLY && defined _MSC_VER && _MSC_VER <= 1900
-    // Visual Studio 2015
-template<char C> struct ExceptCharArrayDetector<OUStringLiteral1<C>> {};
+#if defined LIBO_INTERNAL_ONLY
+template<char C> struct ExceptCharArrayDetector<OUStringLiteral1_<C>> {};
 #endif
 
 template< typename T1, typename T2 = void >

sal/qa/rtl/strings/test_oustring_stringliterals.cxx

@@ -228,8 +228,7 @@ void test::oustring::StringLiterals::checkOUStringLiteral1()
 
     // auto l5 = rtlunittest::OUStringLiteral1<sal_Unicode(0x100)>();
 
-    rtl::OUString s1;
-    s1 = rtlunittest::OUStringLiteral1<'A'>();
+    rtl::OUString s1{rtlunittest::OUStringLiteral1<'A'>()};
     CPPUNIT_ASSERT_EQUAL(sal_Int32(1), s1.getLength());
     CPPUNIT_ASSERT_EQUAL(sal_Unicode('A'), s1[0]);