As of r36306 [1], the behavior of action=edit's md5 parameter in
conjunction with the appendtext and prependtext parameters has changed.
Instead of requiring the MD5 hash of the entire article text (which
makes appendtext and prependtext kind of useless), the md5 parameter now
requires the hash of the concatenation of the prependtext and the
appendtext parameter. For example, if you set
prependtext=Foo&appendtext=bar , you'll need to set the md5 parameter to
the result of md5('Foobar') .
Roan Kattouw (Catrope)
[1]
http://svn.wikimedia.org/viewvc/mediawiki?view=rev&revision=36306