Extract translatable strings alongside their doctree nodes.

sphinx/builders/intl.py

@@ -64,7 +64,7 @@ class MessageCatalogBuilder(Builder):
         otherwise its *name* -- is considered its section.
         """
         catalog = self.catalogs[docname.split('/')[0]]
-        for msg in extract_messages(doctree):
+        for _, msg in extract_messages(doctree):
             # XXX msgctxt for duplicate messages
             if msg not in catalog:
                 catalog.append(msg)

sphinx/util/nodes.py

@@ -30,7 +30,7 @@ def extract_messages(doctree):
         msg = node.astext().replace('\n', ' ').strip()
         # XXX nodes rendering empty are likely a bug in sphinx.addnodes
         if msg:
-            yield msg
+            yield node, msg
 
 
 def nested_parse_with_titles(state, content, node):