Permit XML entities to be escaped in template output. Useful for creating XML documents directly from Hg logging. Can also be used for HTML. For use in content, will escape '&', '<', and for completeness '>' (although it is not strictly necessary). For use in attributes, will also escape ' and ". Will also replace nonprinting (ASCII) control characters with spaces, since these are illegal in XML.

--- a/tests/test-command-template	Sun Feb 24 17:58:55 2008 +0100
+++ b/tests/test-command-template	Mon Jan 28 22:19:12 2008 -0500
@@ -106,6 +106,7 @@
 hg log --template '{date|rfc822date}\n'
 hg log --template '{desc|firstline}\n'
 hg log --template '{node|short}\n'
+hg log --template '<changeset author="{author|xmlescape}"/>\n'
 
 echo '# formatnode filter works'
 echo '#  quiet'