setuid confusion

[Alex LeDonne]

I just found a snippet on
http://www.linux-knowledge-portal.org/en/content.php?&content/programming/secprog2.html
:

"The access(2) call uses the real UID and real GID to check the
rights. This means that the effective UID/GID of SetUID/-GID programs
does not apply. In the case of the access check with open(2), on the
other hand, the effective UID/GID is used."

So if svn is using access(2) instead of open(2) to check perms on the
lock file, your system() call won't work.

I haven't tried to look at subversion source yet to see...

-Alex L