Fix RstReader authors metadata processing

The reader would return a list of authors already, but
METADATA_PROCESSORS['authors'] expects a string.
Added a test case for this (only the HTMLReader had it).

pelican/readers.py

@@ -145,6 +145,7 @@ class RstReader(BaseReader):
                 elif element.tagname == 'authors':  # author list
                     name = element.tagname
                     value = [element.astext() for element in element.children]
+                    value = ','.join(value) # METADATA_PROCESSORS expects a string
                 else:  # standard fields (e.g. address)
                     name = element.tagname
                     value = element.astext()

pelican/tests/test_generators.py

@@ -109,6 +109,7 @@ class TestArticlesGenerator(unittest.TestCase):
             ['This is an article with category !', 'published', 'yeah',
              'article'],
             ['This is an article with multiple authors!', 'published', 'Default', 'article'],
+            ['This is an article with multiple authors!', 'published', 'Default', 'article'],
             ['This is an article without category !', 'published', 'Default',
              'article'],
             ['This is an article without category !', 'published',

pelican/tests/test_readers.py

@@ -150,6 +150,15 @@ class RstReaderTest(ReaderTest):
         except ImportError:
             return unittest.skip('need the typogrify distribution')
 
+    def test_article_with_multiple_authors(self):
+        page = self.read_file(path='article_with_multiple_authors.rst')
+        expected = {
+            'authors': ['First Author', 'Second Author']
+        }
+
+        for key, value in expected.items():
+            self.assertEqual(value, page.metadata[key], key)
+
 
 class MdReaderTest(ReaderTest):