hgweb: move prettyprintlines() closure out of diffs()

This will be wrapped with mappedgenerator.

mercurial/hgweb/webutil.py

@@ -519,10 +519,7 b' def listfilediffs(files, node, max):'
     return templateutil.mappedgenerator(_listfilediffsgen,
                                         args=(files, node, max))
 
-def diffs(web, ctx, basectx, files, style, linerange=None,
-          lineidprefix=''):
-
-    def prettyprintlines(lines, blockno):
+def _prettyprintdifflines(tmpl, lines, blockno, lineidprefix):
         for lineno, l in enumerate(lines, 1):
             difflineno = "%d.%d" % (blockno, lineno)
             if l.startswith('+'):
@@ -533,13 +530,15 b' def diffs(web, ctx, basectx, files, styl'
                 ltype = "difflineat"
             else:
                 ltype = "diffline"
-            yield web.tmpl.generate(ltype, {
+        yield tmpl.generate(ltype, {
                 'line': l,
                 'lineno': lineno,
                 'lineid': lineidprefix + "l%s" % difflineno,
                 'linenumber': "% 8s" % difflineno,
             })
 
+def diffs(web, ctx, basectx, files, style, linerange=None,
+          lineidprefix=''):
     repo = web.repo
     if files:
         m = match.exact(repo.root, repo.getcwd(), files)
@@ -566,7 +565,8 b' def diffs(web, ctx, basectx, files, styl'
             yield web.tmpl.generate('diffblock', {
                 'parity': next(parity),
                 'blockno': blockno,
-                'lines': prettyprintlines(lines, blockno),
+                'lines': _prettyprintdifflines(web.tmpl, lines, blockno,
+                                               lineidprefix),
             })
 
 def compare(tmpl, context, leftlines, rightlines):