Do not edit obsolete units

trans/formats.py

@@ -385,8 +385,12 @@ class FileFormat(object):
                     raise Exception(
                         'Could not find template unit for new unit!'
                     )
+                if template_ttkit_unit.isobsolete():
+                    return (None, False)
                 add = True
             else:
+                if ttkit_unit.isobsolete():
+                    return (None, False)
                 add = False
 
             return (FileUnit(ttkit_unit, template_ttkit_unit), add)
@@ -396,6 +400,8 @@ class FileFormat(object):
             # Find is broken for propfile, ignore results
             if len(found_units) > 0 and not isinstance(self.store, propfile):
                 for ttkit_unit in found_units:
+                    if ttkit_unit.isobsolete():
+                        continue
                     # Does context match?
                     if ttkit_unit.getcontext() == context:
                         return (FileUnit(ttkit_unit), False)
@@ -403,6 +409,8 @@ class FileFormat(object):
                 # Fallback to manual find for value based files
                 for ttkit_unit in self.store.units:
                     ttkit_unit = FileUnit(ttkit_unit)
+                    if ttkit_unit.isobsolete():
+                        continue
                     if ttkit_unit.get_source() == source:
                         return (ttkit_unit, False)