extdiff: enable -I/-X with --patch

Not sure how useful this really is, but it's trivial to add and ignoring the
existing arguments supported seems like a bad UI.

hgext/extdiff.py

@@ -223,10 +223,10 b' def dodiff(ui, repo, cmdline, pats, opts'
                 dir2 = os.path.join(dir2root, dir2, common_file)
                 label2 = common_file + rev2
         else:
-            # XXX: export doesn't support -I/-X like extdiff does
             template = 'hg-%h.patch'
             cmdutil.export(repo, [repo[node1a].rev(), repo[node2].rev()],
-                           template=repo.vfs.reljoin(tmproot, template))
+                           template=repo.vfs.reljoin(tmproot, template),
+                           match=matcher)
             label1a = cmdutil.makefilename(repo, template, node1a)
             label2 = cmdutil.makefilename(repo, template, node2)
             dir1a = repo.vfs.reljoin(tmproot, label1a)

mercurial/cmdutil.py

@@ -992,7 +992,7 b' def tryimportone(ui, repo, hunk, parents'
         os.unlink(tmpname)
 
 def export(repo, revs, template='hg-%h.patch', fp=None, switch_parent=False,
-           opts=None):
+           opts=None, match=None):
     '''export changesets as hg patches.'''
 
     total = len(revs)
@@ -1043,7 +1043,7 b" def export(repo, revs, template='hg-%h.p"
         write(ctx.description().rstrip())
         write("\n\n")
 
-        for chunk, label in patch.diffui(repo, prev, node, opts=opts):
+        for chunk, label in patch.diffui(repo, prev, node, match, opts=opts):
             write(chunk, label=label)
 
         if shouldclose:

tests/test-graft.t

@@ -363,6 +363,22 b' Disallow grafting an already grafted cse'
   ++a
   [1]
 
+  $ hg extdiff --config extensions.extdiff= --patch -r 2 -r 13 -X .
+  --- */hg-5c095ad7e90f.patch	* +0000 (glob)
+  +++ */hg-7a4785234d87.patch	* +0000 (glob)
+  @@ -1,8 +1,8 @@
+   # HG changeset patch
+  -# User test
+  +# User foo
+   # Date 0 0
+   #      Thu Jan 01 00:00:00 1970 +0000
+  -# Node ID 5c095ad7e90f871700f02dd1fa5012cb4498a2d4
+  -# Parent  5d205f8b35b66bc36375c9534ffd3237730e8f04
+  +# Node ID 7a4785234d87ec1aa420ed6b11afe40fa73e12a9
+  +# Parent  b592ea63bb0c19a6c5c44685ee29a2284f9f1b8f
+   2
+   
+  [1]
 
 Disallow grafting already grafted csets with the same origin onto each other
   $ hg up -q 13