[PATCH 1 of 3] template: call runtemplate on the src argument to sub

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean.michael.farley at gmail.com>
# Date 1365640069 18000
#      Wed Apr 10 19:27:49 2013 -0500
# Node ID b657a963876cb670bb003ec4c1cacce3189b2055
# Parent  63a783d1ac852d60e60669b2f8551a9b26de2947
template: call runtemplate on the src argument to sub

This allows using a template keyword on calls to the sub function and brings
the function inline with most other semantics of the other template functions.

diff --git a/mercurial/templater.py b/mercurial/templater.py
--- a/mercurial/templater.py
+++ b/mercurial/templater.py
@@ -249,10 +249,12 @@
         raise error.ParseError(_("sub expects three arguments"))
 
     pat = stringify(args[0][0](context, mapping, args[0][1]))
     rpl = stringify(args[1][0](context, mapping, args[1][1]))
     src = stringify(args[2][0](context, mapping, args[2][1]))
+    src = stringify(runtemplate(context, mapping,
+                                compiletemplate(src, context)))
     yield re.sub(pat, rpl, src)
 
 def if_(context, mapping, args):
     if not (2 <= len(args) <= 3):
         # i18n: "if" is a keyword
diff --git a/tests/test-command-template.t b/tests/test-command-template.t
--- a/tests/test-command-template.t
+++ b/tests/test-command-template.t
@@ -1529,5 +1529,9 @@
 Test new-style inline templating:
 
   $ hg log -R latesttag -r tip --template 'modified files: {file_mods % " {file}\n"}\n'
   modified files:  .hgtags
   
+Test the sub function of templating for expansion:
+
+  $ hg log -R latesttag -r 10 --template '{sub("[0-9]", "x", "{rev}")}\n'
+  xx