Hi all,
I am picking apart some strange behaviour where use of the Alias directive
inside a Location along with a file path that doesn’t exist
(/_thumbs/i/dont/exist.jpg) triggers a loop of redirects to
…/index.html/index.html/index.html/…
The loop of redirects is caused by mod_dir being told that the non existent
file is actually a directory (r->finfo.filetype == APR_DIR) instead of a
nonexistent file (r->finfo.filetype == APR_NOFILE). Working backwards to find
where a non existent file is being mislabelled as a directory, it leads me to
ap_directory_walk(), specifically these lines:
do {
[snip]
if (*seg_name == '/')
++seg_name;
/* If nothing remained but a '/' string, we are finished
* XXX: NO WE ARE NOT!!! Now process this puppy!!! */
if (!*seg_name) {
break;
}
[snip]
} while (thisinfo.filetype == APR_DIR);
What is happening is that we are reaching the break, which aborts the loop but
leaves the value thisinfo.filetype == APR_DIR, thus triggering the downstream
mod_dir mayhem.
Further down in the loop, we have some code that looks like this that
explicitly sets the file to APR_NOFILE before breaking:
if (APR_STATUS_IS_ENOENT(rv)) {
/* Nothing? That could be nice. But our directory
* walk is done.
*/
thisinfo.filetype = APR_NOFILE;
break;
}
In theory following the pattern above, we might change the code above to:
if (!*seg_name) {
+ thisinfo.filetype = APR_NOFILE;
break;
}
However I don’t fully understand what the comment "XXX: NO WE ARE NOT!!! Now
process this puppy!!!” actually means.
Can anyone confirm?
Regards,
Graham
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