do not make PTY slave the controlling terminal

If we have no controlling terminal opening a terminal will make this
terminal our controller, which is a serious problem if this happens to
be the pseudo terminal we created to run dpkg in as we will close this
terminal at the end hanging ourself up in the process…

The offending open is the one we do to have at least one slave fd open
all the time, but for good measure, we apply the flag also to the slave
fd opening in the child process as we set the controlling terminal
explicitely here.

This is a regression from 150bdc9ca5d656f9fba94d37c5f4f183b02bd746 with
the slight twist that this usecase was silently broken before in that it
wasn't logging the output in term.log (as a pseudo terminal wasn't
created).

Closes: 772641

apt-pkg/deb/dpkgpm.cc

@@ -1131,7 +1131,7 @@ void pkgDPkgPM::StartPtyMagic()
 	       on kfreebsd we get an incorrect ("step like") output then while it has
 	       no problem with closing all references… so to avoid platform specific
 	       code here we combine both and be happy once more */
-	    d->protect_slave_from_dying = open(d->slave, O_RDWR | O_CLOEXEC);
+	    d->protect_slave_from_dying = open(d->slave, O_RDWR | O_CLOEXEC | O_NOCTTY);
 	 }
       }
    }
@@ -1163,7 +1163,7 @@ void pkgDPkgPM::SetupSlavePtyMagic()
    if (setsid() == -1)
       _error->FatalE("setsid", "Starting a new session for child failed!");
 
-   int const slaveFd = open(d->slave, O_RDWR);
+   int const slaveFd = open(d->slave, O_RDWR | O_NOCTTY);
    if (slaveFd == -1)
       _error->FatalE("open", _("Can not write log (%s)"), _("Is /dev/pts mounted?"));
    else if (ioctl(slaveFd, TIOCSCTTY, 0) < 0)

test/integration/framework

@@ -102,7 +102,7 @@ runapt() {
 	local CMD="$1"
 	shift
 	case $CMD in
-	sh|aptitude|*/*) ;;
+	sh|aptitude|*/*|command) ;;
 	*) CMD="${BUILDDIRECTORY}/$CMD";;
 	esac
 	MALLOC_PERTURB_=21 MALLOC_CHECK_=2 APT_CONFIG="$(getaptconfig)" LD_LIBRARY_PATH=${BUILDDIRECTORY} $CMD "$@"

test/integration/test-no-fds-leaked-to-maintainer-scripts

@@ -5,7 +5,7 @@ TESTDIR=$(readlink -f $(dirname $0))
 . $TESTDIR/framework
 
 setupenvironment
-configarchitecture 'native'
+configarchitecture 'amd64' 'i386'
 configdpkgnoopchroot
 
 setupsimplenativepackage "fdleaks" 'all' '1.0' 'unstable'
@@ -17,58 +17,83 @@ done
 buildpackage "$BUILDDIR" 'unstable' 'main' 'native'
 rm -rf "$BUILDDIR"
 
+PKGNAME='fdleaks:all'
+if ! dpkg-checkbuilddeps -d 'dpkg (>= 1.16.2)' /dev/null >/dev/null 2>&1; then
+	PKGNAME='fdleaks'
+fi
+
 setupaptarchive
 
 rm -f rootdir/var/log/dpkg.log rootdir/var/log/apt/term.log
 testsuccess aptget install -y fdleaks -qq < /dev/null
-msgtest 'Check if fds were not' 'leaked'
-if [ "$(grep 'root root' rootdir/tmp/testsuccess.output | wc -l)" = '8' ]; then
-	msgpass
-else
-	echo
-	cat rootdir/tmp/testsuccess.output
-	msgfail
-fi
 
-cp rootdir/tmp/testsuccess.output terminal.output
-tail -n +3 rootdir/var/log/apt/term.log | head -n -1 > terminal.log
-testfileequal 'terminal.log' "$(cat terminal.output)"
+checkfdleak() {
+	msgtest 'Check if fds were not' 'leaked'
+	if [ "$(grep 'root root' rootdir/tmp/testsuccess.output | wc -l)" = "$1" ]; then
+		msgpass
+	else
+		echo
+		cat rootdir/tmp/testsuccess.output
+		msgfail
+	fi
+}
+checkinstall() {
+	checkfdleak 8
+
+	cp rootdir/tmp/testsuccess.output terminal.output
+	tail -n +3 rootdir/var/log/apt/term.log | head -n -1 > terminal.log
+	testfileequal 'terminal.log' "$(cat terminal.output)"
 
-testequal 'startup archives unpack
-install fdleaks:all <none> 1.0
-status half-installed fdleaks:all 1.0
-status unpacked fdleaks:all 1.0
-status unpacked fdleaks:all 1.0
+	testequal "startup archives unpack
+install $PKGNAME <none> 1.0
+status half-installed $PKGNAME 1.0
+status unpacked $PKGNAME 1.0
+status unpacked $PKGNAME 1.0
 startup packages configure
-configure fdleaks:all 1.0 <none>
-status unpacked fdleaks:all 1.0
-status half-configured fdleaks:all 1.0
-status installed fdleaks:all 1.0' cut -f 3- -d' ' rootdir/var/log/dpkg.log
+configure $PKGNAME 1.0 <none>
+status unpacked $PKGNAME 1.0
+status half-configured $PKGNAME 1.0
+status installed $PKGNAME 1.0" cut -f 3- -d' ' rootdir/var/log/dpkg.log
+}
+checkinstall
 
 rm -f rootdir/var/log/dpkg.log rootdir/var/log/apt/term.log
 testsuccess aptget purge -y fdleaks -qq
-msgtest 'Check if fds were not' 'leaked'
-if [ "$(grep 'root root' rootdir/tmp/testsuccess.output | wc -l)" = '12' ]; then
+checkpurge() {
+	checkfdleak 12
+
+	cp rootdir/tmp/testsuccess.output terminal.output
+	tail -n +3 rootdir/var/log/apt/term.log | head -n -1 > terminal.log
+	testfileequal 'terminal.log' "$(cat terminal.output)"
+
+	testequal "startup packages purge
+status installed $PKGNAME 1.0
+remove $PKGNAME 1.0 <none>
+status half-configured $PKGNAME 1.0
+status half-installed $PKGNAME 1.0
+status config-files $PKGNAME 1.0
+purge $PKGNAME 1.0 <none>
+status config-files $PKGNAME 1.0
+status config-files $PKGNAME 1.0
+status config-files $PKGNAME 1.0
+status config-files $PKGNAME 1.0
+status config-files $PKGNAME 1.0
+status not-installed $PKGNAME <none>" cut -f 3- -d' ' rootdir/var/log/dpkg.log
+}
+checkpurge
+
+msgtest 'setsid provided is new enough to support' '-w'
+if dpkg-checkbuilddeps -d 'util-linux (>= 2.24.2-1)' /dev/null >/dev/null 2>&1; then
 	msgpass
 else
-	echo
-	cat rootdir/tmp/testsuccess.output
-	msgfail
+	msgskip "$(command dpkg -l util-linux)"
+	exit
 fi
-cp rootdir/tmp/testsuccess.output terminal.output
-tail -n +3 rootdir/var/log/apt/term.log | head -n -1 > terminal.log
-testfileequal 'terminal.log' "$(cat terminal.output)"
 
-testequal 'startup packages purge
-status installed fdleaks:all 1.0
-remove fdleaks:all 1.0 <none>
-status half-configured fdleaks:all 1.0
-status half-installed fdleaks:all 1.0
-status config-files fdleaks:all 1.0
-purge fdleaks:all 1.0 <none>
-status config-files fdleaks:all 1.0
-status config-files fdleaks:all 1.0
-status config-files fdleaks:all 1.0
-status config-files fdleaks:all 1.0
-status config-files fdleaks:all 1.0
-status not-installed fdleaks:all <none>' cut -f 3- -d' ' rootdir/var/log/dpkg.log
+rm -f rootdir/var/log/dpkg.log rootdir/var/log/apt/term.log
+testsuccess runapt command setsid -w "${BUILDDIRECTORY}/apt-get" install -y fdleaks -qq < /dev/null
+checkinstall
+
+rm -f rootdir/var/log/dpkg.log rootdir/var/log/apt/term.log
+testsuccess runapt command setsid -w "${BUILDDIRECTORY}/apt-get" purge -y fdleaks -qq
+checkpurge