meek-client-torbrowser should exit on stdin close, even while waiting on browser output
Edit the browser extension not to output the
meek-http-helper: listen line, or hack meek-client-torbrowser to break
grepHelperAddress. Start Tor Launcher, select meek, and Connect. Now Cancel and exit Tor Browser. The bug is that meek-client-torbrowser and its child process firefox will continue running.
It happens because meek-client-torbrowser's
TOR_PT_EXIT_ON_STDIN_CLOSE and SIGTERM logic happen only after
grepHelperAddr. meek-client-torbrowser should pay attention to its stdin the whole time so that it can exit correctly in this case.