Fatal error when $XDG_CONFIG_HOME/XCompose is a directory

[Janno]

I am getting this error message from software that uses xkbcommon:

xkbcommon: ERROR: Couldn't read Compose file /home/janno/.config/XCompose: No such device

~/.config/XCompose is a directory in my case and what is failing here is a call to mmap on that directory. I don't think mmap should be called on directories?

strace reports:

[pid 567663] openat(AT_FDCWD, "/home/janno/.config/XCompose", O_RDONLY) = 4
[pid 567663] newfstatat(4, "", {st_mode=S_IFDIR|0755, st_size=10, ...}, AT_EMPTY_PATH) = 0
[pid 567663] mmap(NULL, 10, PROT_READ, MAP_SHARED, 4, 0) = -1 ENODEV (No such device)
[pid 567663] write(2, "xkbcommon: ERROR: ", 18xkbcommon: ERROR: ) = 18
[pid 567663] write(2, "Couldn't read Compose file /home/janno/.config/XCompose: No such device\n", 72Couldn't read Compose file /home/janno/.config/XCompose: No such device
) = 72

I am not 100% sure that this is xkbcommon's fault but I did check the documentation and the docs for xkb_compose_table_new_from_locale make it sound like xkbcommon is the one that decides to open this file.

[wismill]

Indeed, this is one of the paths that are checked. We do not check whether it is a regular file though. A temporary workaround is to rename your directory.

MR welcome!

[whot]

Maybe the easiest fix here is to open() and then on success fdopen().

[wismill]

Maybe the easiest fix here is to open() and then on success fdopen().

@whot how would you do that?

I opened #441 with another approach.

[whot]

/me types code /me reads man page

nevermind, what I had in mind (catching EISDIR) won't work since we only open readonly. So your stat approach is the correct one, see my comment re: race condition there though please.