Fix YAML parser bug

djangorestframework/parsers.py

@@ -92,7 +92,6 @@ class JSONParser(BaseParser):
                                 {'detail': 'JSON parse error - %s' % unicode(exc)})
 
 
-if yaml:
 class YAMLParser(BaseParser):
     """
     Parses YAML-serialized data.
@@ -109,11 +108,9 @@ if yaml:
         """
         try:
             return (yaml.safe_load(stream), None)
-            except ValueError, exc:
-                raise ErrorResponse(status.HTTP_400_BAD_REQUEST,
-                                    {'detail': 'YAML parse error - %s' % unicode(exc)})
-else:
-    YAMLParser = None
+        except (ValueError, yaml.parser.ParserError), exc:
+            content = {'detail': 'YAML parse error - %s' % unicode(exc)}
+            raise ErrorResponse(status.HTTP_400_BAD_REQUEST, content)
 
 
 class PlainTextParser(BaseParser):
@@ -248,5 +245,8 @@ DEFAULT_PARSERS = (
     XMLParser
 )
 
-if YAMLParser:
+if yaml:
     DEFAULT_PARSERS += (YAMLParser, )
+else:
+    YAMLParser = None
+

djangorestframework/renderers.py

@@ -152,7 +152,6 @@ class XMLRenderer(BaseRenderer):
         return dict2xml(obj)
 
 
-if yaml:
 class YAMLRenderer(BaseRenderer):
     """
     Renderer which serializes to YAML.
@@ -169,8 +168,6 @@ if yaml:
             return ''
 
         return yaml.safe_dump(obj)
-else:
-    YAMLRenderer = None
 
 
 class TemplateRenderer(BaseRenderer):
@@ -409,5 +406,7 @@ DEFAULT_RENDERERS = (
     XMLRenderer
 )
 
-if YAMLRenderer:
+if yaml:
     DEFAULT_RENDERERS += (YAMLRenderer, )
+else:
+    YAMLRenderer = None