Consider an authz file:
[/]
pm = rw
PM = r
When we parse the key=value lines we handle the key case-insensitively so only
one value, the last, gets stored as the second value overrides the first.
However we also store the exact case of the first key and that is what is
checked when querying:
$ svnauthz accessof authz.txt --username PM
no
$ svnauthz accessof authz.txt --username pm
r
the effective line is "pm = r" which is not something that occurs in the file.
dev thread:
http://mail-archives.apache.org/mod_mbox/subversion-dev/201304.mbox/%3C87ppxk55kl.fsf@ntlworld.com%3E
http://svn.haxx.se/dev/archive-2013-04/0541.shtml