Fix #2558: unpack error on devhelp builder

Author: tk0miya

CHANGES

@@ -60,6 +60,7 @@ Bugs fixed
 * #2470: ``typing`` backport package causes autodoc errors with python 2.7
 * ``sphinx.ext.intersphinx`` crashes if non-string value is used for key of `intersphinx_mapping`
 * #2518: `intersphinx_mapping` disallows non alphanumeric keys
+* #2558: unpack error on devhelp builder
 
 
 Release 1.4.1 (released Apr 12, 2016)

sphinx/builders/devhelp.py

@@ -123,7 +123,7 @@ def write_index(title, refs, subitems):
                                 subitem[1], [])
 
         for (key, group) in index:
-            for title, (refs, subitems) in group:
+            for title, (refs, subitems, key) in group:
                 write_index(title, refs, subitems)
 
         # Dump the XML file