# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 2014-08-30 18:06:24
# Node ID e284de138f00676f33a0d8a390dd79fafcf5087d
# Parent  e1d5fcab58b6c135c0e26546af2baf1a0c39f978

help: only call doc() when it is callable

`hg help -k` on my machine was aborting because the hg-prompt extension
was inserting a string and not a function into help.helptable and help
was blindly calling it.

This patch changes keyword searching to be more robust against
unexpected types.

diff --git a/mercurial/help.py b/mercurial/help.py
--- a/mercurial/help.py
+++ b/mercurial/help.py
@@ -86,9 +86,10 @@ def topicmatch(kw):
                'extensioncommands': [],
                }
     for names, header, doc in helptable:
+        # Old extensions may use a str as doc.
         if (sum(map(lowercontains, names))
             or lowercontains(header)
-            or lowercontains(doc())):
+            or (callable(doc) and lowercontains(doc()))):
             results['topics'].append((names[0], header))
     import commands # avoid cycle
     for cmd, entry in commands.table.iteritems():