The X11 lock file was somewhat opaque. Into a sized array of 16
characters, we previously read 11 bytes. 61beda653b fixed the parsing of
this input to ensure that we only considered the first 10 bytes: this
has the effect of culling a LF byte at the end of the string.
This commit more explicitly NULLs the entire string before reading, and
trims trailing LF characters only.
It also adds some documentation by way of resizing pid, an explicit size
check on snprintf's return, and comments.
Verified manually that it emits lock files with a trailing \n, as Xorg
does. Also verified manually that it ignores misformatted lock files,
but accepts either \n or \0 in the trailing position.
Related Mutter issue: https://bugzilla.gnome.org/show_bug.cgi?id=774613
Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Daniel Stone
08a35d307f