From 4917b8618aa71221f640bbf749cee7944eba32f3 Mon Sep 17 00:00:00 2001
From: Tim Wienk <tim@wienk.name>
Date: Sat, 11 Mar 2017 13:38:54 +0100
Subject: [PATCH] Fix setting None metadata from FILENAME_METADATA matches.

This is relevant when using optional items in the expression. E.g. if an
optional captured group is not matched, the result of
`match.groupdict()` contains the captured group with value `None`.
---
 pelican/readers.py            |  2 +-
 pelican/tests/test_readers.py | 38 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/pelican/readers.py b/pelican/readers.py
index e899838a..a620a1e8 100644
--- a/pelican/readers.py
+++ b/pelican/readers.py
@@ -672,7 +672,7 @@ def parse_path_metadata(source_path, settings=None, process=None):
                     # .items() for py3k compat.
                     for k, v in match.groupdict().items():
                         k = k.lower()  # metadata must be lowercase
-                        if k not in metadata:
+                        if v is not None and k not in metadata:
                             if process:
                                 v = process(k, v)
                             metadata[k] = v
diff --git a/pelican/tests/test_readers.py b/pelican/tests/test_readers.py
index ac0f81dc..0d22bf44 100644
--- a/pelican/tests/test_readers.py
+++ b/pelican/tests/test_readers.py
@@ -166,6 +166,25 @@ class RstReaderTest(ReaderTest):
         }
         self.assertDictHasSubset(page.metadata, expected)
 
+    def test_article_with_optional_filename_metadata(self):
+        page = self.read_file(
+            path='2012-11-29_rst_w_filename_meta#foo-bar.rst',
+            FILENAME_METADATA='(?P<date>\d{4}-\d{2}-\d{2})?')
+        expected = {
+            'date': SafeDatetime(2012, 11, 29),
+            'reader': 'rst',
+        }
+        self.assertDictHasSubset(page.metadata, expected)
+
+        page = self.read_file(
+            path='article.rst',
+            FILENAME_METADATA='(?P<date>\d{4}-\d{2}-\d{2})?')
+        expected = {
+            'reader': 'rst',
+        }
+        self.assertDictHasSubset(page.metadata, expected)
+        self.assertNotIn('date', page.metadata, 'Date should not be set.')
+
     def test_article_metadata_key_lowercase(self):
         # Keys of metadata should be lowercase.
         reader = readers.RstReader(settings=get_settings())
@@ -561,6 +580,25 @@ class MdReaderTest(ReaderTest):
         }
         self.assertDictHasSubset(page.metadata, expected)
 
+    def test_article_with_optional_filename_metadata(self):
+        page = self.read_file(
+            path='2012-11-30_md_w_filename_meta#foo-bar.md',
+            FILENAME_METADATA='(?P<date>\d{4}-\d{2}-\d{2})?')
+        expected = {
+            'date': SafeDatetime(2012, 11, 30),
+            'reader': 'markdown',
+        }
+        self.assertDictHasSubset(page.metadata, expected)
+
+        page = self.read_file(
+            path='empty.md',
+            FILENAME_METADATA='(?P<date>\d{4}-\d{2}-\d{2})?')
+        expected = {
+            'reader': 'markdown',
+        }
+        self.assertDictHasSubset(page.metadata, expected)
+        self.assertNotIn('date', page.metadata, 'Date should not be set.')
+
     def test_duplicate_tags_or_authors_are_removed(self):
         reader = readers.MarkdownReader(settings=get_settings())
         content, metadata = reader.read(