configure-time problem with tcsetpgrp test (again)

[Adam Spiers <adam@spiers.net>]

I just got this weird problem when running ./configure.  It only
happens when I redirect stdout from the configure to a file.  When the
`checking if POSIX sigsuspend() works... yes' line is reached, the
configure process gets suspended.  If I tail -f the log file at the
same time it looks like this:


checking if named FIFOs work... yes
checking if echo in /bin/sh interprets escape sequences... no
checking if link() works... yes
checking if kill(pid, 0) returns ESRCH correctly... yes
Waiting for data... (interrupt to abort)[1]  + 17124 suspended (tty output)  ./configure --prefix=/usr --bindir=/bin --enable-etcdir=/etc  >| foo
checking if POSIX sigsuspend() works... yes
Waiting for data... (interrupt to abort)


config.log (and also sometimes the log file I redirected to) always
indicates that the tcsetpgrp() test two tests later always gets
reached before the process gets suspended; could it be this test which
causes the problems instead?  I noticed from the archives that this
tcsetpgrp() has been the cause of trouble in the past ... ah, wait a
minute.  It's the `-t 0 -a' bit which is going wrong, isn't it?  The
test should be skipped, but isn't being?  If I insert a `</dev/null'
on the command line for configure then the test gets skipped and all
is well.  Should there be a `-t 1 -a -t 2 -a' as well or something?

Adam