Line break in link references inside lists

[vincentbernat]

Hey!

Consider the following code:

Two things:

 - I would like to tell you about the [code of
   conduct][] we are using in this project.
 - Only one in fact.

[code of conduct]: https://github.com/Python-Markdown/markdown/blob/master/CODE_OF_CONDUCT.md

CommonMark is rendering the link correctly. GitHub as well (see below). PHP Markdown does render correctly too. However, Python-Markdown doesn't because of the space at the beginning of the line. I don't know if space at the beginning of a line should just be ignored inside a link or if only the exact amount of space used for list indent should be ignored.

---

Two things:

• I would like to tell you about the code of
  conduct we are using in this project.
• Only one in fact.

[facelessuser]

I took a look at this. It looks like we have bad id cleanup. I have a patch that I'll make a pull request for once I test it more.

diff --git a/markdown/inlinepatterns.py b/markdown/inlinepatterns.py
index 3d3e65f..dc502c2 100644
--- a/markdown/inlinepatterns.py
+++ b/markdown/inlinepatterns.py
@@ -617,7 +617,7 @@ class ImageInlineProcessor(LinkInlineProcessor):

 class ReferenceInlineProcessor(LinkInlineProcessor):
     """ Match to a stored reference and return link element. """
-    NEWLINE_CLEANUP_RE = re.compile(r'[ ]?\n', re.MULTILINE)
+    NEWLINE_CLEANUP_RE = re.compile(r'\s+', re.MULTILINE)

     RE_LINK = re.compile(r'\s?\[([^\]]*)\]', re.DOTALL | re.UNICODE)