Make same check better behave on different source languages

- do not run it on template strings
- do not run it on translation to source language
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/checks/same.py

@@ -178,11 +178,21 @@ class SameCheck(TargetCheck):
         return result
 
     def check_single(self, source, target, unit):
+        translation = unit.translation
+        # Ignore this on templates
+        if translation.is_template():
+            return False
+
         # English variants will have most things not translated
         # Interlingua is also quite often similar to English
         if self.is_language(unit, ('en', 'ia')):
             return False
 
+        # Ignore the check for source language
+        if (translation.language ==
+                translation.subproject.project.source_language):
+            return False
+
         # One letter things are usually labels or decimal/thousand separators
         if len(source) <= 1 and len(target) <= 1:
             return False

weblate/trans/tests/test_checks.py

@@ -61,6 +61,9 @@ class MockTranslation(object):
         self.language = MockLanguage(code)
         self.subproject = MockSubProject()
 
+    def is_template(self):
+        return False
+
 
 class MockUnit(object):
     '''