--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-custom-filters.t	Mon Aug 30 18:57:48 2010 +0900
@@ -0,0 +1,69 @@
+  $ hg init
+
+  $ cat > .hg/hgrc <<EOF
+  > [extensions]
+  > prefixfilter = prefix.py
+  > [encode]
+  > *.txt = stripprefix: Copyright 2046, The Masters
+  > [decode]
+  > *.txt = insertprefix: Copyright 2046, The Masters
+  > EOF
+
+  $ cat > prefix.py <<EOF
+  > from mercurial import util
+  > def stripprefix(s, cmd, filename, **kwargs):
+  >     header = '%s\n' % cmd
+  >     if s[:len(header)] != header:
+  >         raise util.Abort('missing header "%s" in %s' % (cmd, filename))
+  >     return s[len(header):]
+  > def insertprefix(s, cmd):
+  >     return '%s\n%s' % (cmd, s)
+  > def reposetup(ui, repo):
+  >     repo.adddatafilter('stripprefix:', stripprefix)
+  >     repo.adddatafilter('insertprefix:', insertprefix)
+  > EOF
+
+  $ cat > .hgignore <<EOF
+  > .hgignore
+  > prefix.py
+  > prefix.pyc
+  > EOF
+
+  $ cat > stuff.txt <<EOF
+  > Copyright 2046, The Masters
+  > Some stuff to ponder very carefully.
+  > EOF
+  $ hg add stuff.txt
+  $ hg ci -m stuff
+
+Repository data:
+
+  $ hg cat stuff.txt
+  Some stuff to ponder very carefully.
+
+Fresh checkout:
+
+  $ rm stuff.txt
+  $ hg up -C
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat stuff.txt
+  Copyright 2046, The Masters
+  Some stuff to ponder very carefully.
+  $ echo >> stuff.txt <<EOF
+  > Very very carefully.
+  > EOF
+  $ hg stat
+  M stuff.txt
+
+  $ cat > morestuff.txt <<EOF
+  > Unauthorized material subject to destruction.
+  > EOF
+
+Problem encoding:
+
+  $ hg add morestuff.txt
+  $ hg ci -m morestuff
+  abort: missing header "Copyright 2046, The Masters" in morestuff.txt
+  $ hg stat
+  M stuff.txt
+  A morestuff.txt