The url to source file of the api module action=sitematrix is wrong:
current file: http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/api/SiteMatrix_body.php
that url gives an exception: trunk/phase3/includes/api/SiteMatrix_body.php: unknown location
The right file is: http://svn.wikimedia.org/viewvc/mediawiki/trunk/extensions/SiteMatrix/SiteMatrix_body.php
Version: unspecified
Severity: trivial
URL: http://de.wikipedia.org/w/api.php?action=help&version
Assumption is not valid; some directories contain extension entry point files with different names. Use the path that's provided in the version information, rather than throwing it away and attempting to guess it again.
(In reply to comment #3)
Assumption is not valid; some directories contain extension entry point files
with different names.
Names of the entry point files are not relevant and aren't guessed. The only assumption made is this: if the local path to the file does not contain /includes/api and does contain /extensions , then the path is assumed to be /something/extensions/ExtensionName/whatever.php , which I think is a reasonable assumption to make.
Use the path that's provided in the version information,
rather than throwing it away and attempting to guess it again.
And just how would I get that path?