Fix a bug in UnorderedEqualsMatcher

Previously a mismatched prefix would be skipped before the actual
comparison would be performed. Obviously, it is supposed to be
_matching_ prefix that is skipped.

projects/SelfTest/UsageTests/Matchers.tests.cpp

@@ -423,6 +423,15 @@ namespace { namespace MatchersTests {
             }
         }
 
+        TEST_CASE("Regression test #1", "[matchers][vector]") {
+            // At some point, UnorderedEqualsMatcher skipped
+            // mismatched prefixed before doing the comparison itself
+            std::vector<char> actual = { 'a', 'b' };
+            std::vector<char> expected = { 'c', 'b' };
+
+            CHECK_THAT(actual, !UnorderedEquals(expected));
+        }
+
 } } // namespace MatchersTests
 
 #endif // CATCH_CONFIG_DISABLE_MATCHERS