imv: don't rely on glibc's lack of FILE sync on exit.

This issue was spotted on musl, where killing imv with the Q shortcut
while it was waiting for image paths in stdin led to the application
hanging until stdin received an EOF manually with ^D, since the stdin
stream was locked by the fgets() function.

Switching to pipes and a helper thread allows us to use read() for
reading from STDIN_FILENO while still taking advantage of the fgets()
logic for handling newlines and buffer size. read() is a thread
cancellation point (fgets() is only an optional one), which makes it
possible to cancel the helper thread cleanly and force the thread using
fgets() to exit when the write-end of the pipe it's reading from is
closed.

0 files changed, 0 insertions, 0 deletions