Fix #2394: Sphinx crashes when html_last_updated_fmt is invalid

6 files changed, 24 insertions, 6 deletions

diff --git a/CHANGES b/CHANGES
index 47a704b3e..23ff3819b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -16,6 +16,7 @@ Bugs fixed
 * C++, added support for ``extern`` and ``thread_local``.
 * C++, type declarations are now using the prefixes ``typedef``, ``using``, and ``type``,
   depending on the style of declaration.
+* #2394: Fix Sphinx crashes when html_last_updated_fmt is invalid
 
 
 Release 1.4 (released Mar 28, 2016)
diff --git a/sphinx/builders/epub.py b/sphinx/builders/epub.py
index d1610bda9..265421d2c 100644
--- a/sphinx/builders/epub.py
+++ b/sphinx/builders/epub.py
@@ -530,7 +530,8 @@ class EpubBuilder(StandaloneHTMLBuilder):
         metadata['copyright'] = self.esc(self.config.epub_copyright)
         metadata['scheme'] = self.esc(self.config.epub_scheme)
         metadata['id'] = self.esc(self.config.epub_identifier)
-        metadata['date'] = self.esc(format_date('YYYY-MM-dd', language=self.config.language))
+        metadata['date'] = self.esc(format_date('YYYY-MM-dd', language=self.config.language,
+                                                warn=self.warn))
         metadata['files'] = files
         metadata['spine'] = spine
         metadata['guide'] = guide
diff --git a/sphinx/builders/html.py b/sphinx/builders/html.py
index 367e28b8d..1b3db1402 100644
--- a/sphinx/builders/html.py
+++ b/sphinx/builders/html.py
@@ -293,7 +293,8 @@ class StandaloneHTMLBuilder(Builder):
         lufmt = self.config.html_last_updated_fmt
         if lufmt is not None:
             self.last_updated = format_date(lufmt or _('MMM dd, YYYY'),
-                                            language=self.config.language)
+                                            language=self.config.language,
+                                            warn=self.warn)
         else:
             self.last_updated = None
 
diff --git a/sphinx/transforms.py b/sphinx/transforms.py
index 583271116..7272d3b19 100644
--- a/sphinx/transforms.py
+++ b/sphinx/transforms.py
@@ -44,6 +44,7 @@ class DefaultSubstitutions(Transform):
     default_priority = 210
 
     def apply(self):
+        env = self.document.settings.env
         config = self.document.settings.env.config
         # only handle those not otherwise defined in the document
         to_handle = default_substitutions - set(self.document.substitution_defs)
@@ -54,7 +55,7 @@ class DefaultSubstitutions(Transform):
                 if refname == 'today' and not text:
                     # special handling: can also specify a strftime format
                     text = format_date(config.today_fmt or _('MMMM dd, YYYY'),
-                                       language=config.language)
+                                       language=config.language, warn=env.warn)
                 ref.replace_self(nodes.Text(text, text))
 
 
diff --git a/sphinx/util/i18n.py b/sphinx/util/i18n.py
index 94492ff45..5d98b115c 100644
--- a/sphinx/util/i18n.py
+++ b/sphinx/util/i18n.py
@@ -149,7 +149,7 @@ date_format_mappings = {
 }
 
 
-def babel_format_date(date, format, locale):
+def babel_format_date(date, format, locale, warn=None):
     if locale is None:
         locale = 'en'
 
@@ -158,9 +158,15 @@ def babel_format_date(date, format, locale):
     except (ValueError, babel.core.UnknownLocaleError):
         # fallback to English
         return babel.dates.format_date(date, format, locale='en')
+    except AttributeError:
+        if warn:
+            warn('Invalid date format. Quote the string by single quote '
+                 'if you want to output it directly: %s' % format)
 
+        return format
 
-def format_date(format, date=None, language=None):
+
+def format_date(format, date=None, language=None, warn=None):
     if format is None:
         format = 'medium'
 
@@ -175,7 +181,7 @@ def format_date(format, date=None, language=None):
 
     if '%' not in format:
         # consider the format as babel's
-        return babel_format_date(date, format, locale=language)
+        return babel_format_date(date, format, locale=language, warn=warn)
     else:
         warnings.warn('ustrftime format support will be dropped at Sphinx-1.5',
                       DeprecationWarning)
diff --git a/tests/test_util_i18n.py b/tests/test_util_i18n.py
index e84892b5c..a534b2771 100644
--- a/tests/test_util_i18n.py
+++ b/tests/test_util_i18n.py
@@ -185,6 +185,14 @@ def test_format_date():
     assert i18n.format_date(format, date=date, language='ja') == u'2月 07, 2016'
     assert i18n.format_date(format, date=date, language='de') == 'Februar 07, 2016'
 
+    # invalid date format
+    format = 'Mon Mar 28 12:37:08 2016, commit 4367aef'
+    assert i18n.format_date(format, date=date) == format
+
+    # quoted format
+    quoted_format = "'Mon Mar 28 12:37:08 2016, commit 4367aef'"
+    assert i18n.format_date(quoted_format, date=date) == format
+
 
 def test_get_filename_for_language():
     app = TestApp()