Fix #1565: Show warning if Pygments throws an ErrorToken

1 files changed, 5 insertions, 1 deletions

diff --git a/sphinx/highlighting.py b/sphinx/highlighting.py
index 5d2f686dc..aa78b5b2e 100644
--- a/sphinx/highlighting.py
+++ b/sphinx/highlighting.py
@@ -183,9 +183,13 @@ class PygmentsBridge(object):
         formatter = self.get_formatter(**kwargs)
         try:
             hlsource = highlight(source, lexer, formatter)
-        except ErrorToken:
+        except ErrorToken as exc:
             # this is most probably not the selected language,
             # so let it pass unhighlighted
+            if warn:
+                warn('Could not parse literal_block as "%s". highlighting skipped.' % lang)
+            else:
+                raise exc
             hlsource = highlight(source, lexers['none'], formatter)
         if self.dest == 'html':
             return hlsource