[PATCH v2] t1509: update prepare script to be able to run t1509 in chroot again

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Tested on Gentoo and OpenSUSE 13.1, both x86-64

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 On Sun, Apr 12, 2015 at 2:58 AM, Junio C Hamano <gitster@pobox.com> wrote:
 > Duy Nguyen <pclouds@gmail.com> writes:
 >
 >> On Fri, Apr 3, 2015 at 7:01 PM, Jeff King <peff@peff.net> wrote:
 >>> Aside from the nits above, I did get it to run t1509 with this. I can't
 >>> say I'm incredibly excited about the whole thing, if only because it is
 >>> clear that nobody is going to run it regularly (so regressions will
 >>> likely go unnoticed, which is the whole point of the test script).  But
 >>> perhaps it is better than nothing, and it is not hurting anyone to sit
 >>> there and bitrot again. ;)
 >>
 >> To be honest, I didn't run it often in the last 5 years. The code it
 >> protects seems not broken during this time and probably so for a
 >> foreseeable future. So I don't mind if you just kill t1509 and related
 >> scripts.
 >
 > Yeah, but as long as you two worked out to make it run again on at
 > least two systems (i.e. yours), it would be good not to let that
 > effort go to waste. Care to throw a v2 at me with $(id -u) and other
 > changes Peff mentioned?

 thrown (a little bit late because $DAYJOB consumed much of my energy)

 t/t1509/prepare-chroot.sh | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/t/t1509/prepare-chroot.sh b/t/t1509/prepare-chroot.sh
index 6269117..6d47e2c 100755
--- a/t/t1509/prepare-chroot.sh
+++ b/t/t1509/prepare-chroot.sh
@@ -14,25 +14,45 @@ xmkdir() {
 
 R="$1"
 
+[ "$(id -u)" -eq 0 ] && die "This script should not be run as root, what if it does rm -rf /?"
 [ -n "$R" ] || die "usage: prepare-chroot.sh <root>"
 [ -x git ] || die "This script needs to be executed at git source code's top directory"
-[ -x /bin/busybox ] || die "You need busybox"
+if [ -x /bin/busybox ]; then
+	BB=/bin/busybox
+elif [ -x /usr/bin/busybox ]; then
+	BB=/usr/bin/busybox
+else
+	die "You need busybox"
+fi
 
 xmkdir "$R" "$R/bin" "$R/etc" "$R/lib" "$R/dev"
-[ -c "$R/dev/null" ] || die "/dev/null is missing. Do mknod $R/dev/null c 1 3 && chmod 666 $R/dev/null"
+touch "$R/dev/null"
 echo "root:x:0:0:root:/:/bin/sh" > "$R/etc/passwd"
 echo "$(id -nu):x:$(id -u):$(id -g)::$(pwd)/t:/bin/sh" >> "$R/etc/passwd"
 echo "root::0:root" > "$R/etc/group"
 echo "$(id -ng)::$(id -g):$(id -nu)" >> "$R/etc/group"
 
-[ -x "$R/bin/busybox" ] || cp /bin/busybox "$R/bin/busybox"
-[ -x "$R/bin/sh" ] || ln -s /bin/busybox "$R/bin/sh"
-[ -x "$R/bin/su" ] || ln -s /bin/busybox "$R/bin/su"
+[ -x "$R$BB" ] || cp $BB "$R/bin/busybox"
+for cmd in sh su ls expr tr basename rm mkdir mv id uname dirname cat true sed diff; do
+	ln -f -s /bin/busybox "$R/bin/$cmd"
+done
 
 mkdir -p "$R$(pwd)"
 rsync --exclude-from t/t1509/excludes -Ha . "$R$(pwd)"
-ldd git | grep '/' | sed 's,.*\s\(/[^ ]*\).*,\1,' | while read i; do
-	mkdir -p "$R$(dirname $i)"
-	cp "$i" "$R/$i"
+# Fake perl to reduce dependency, t1509 does not use perl, but some
+# env might slip through, see test-lib.sh, unset.*PERL_PATH
+sed 's|^PERL_PATH=.*|PERL_PATH=/bin/true|' GIT-BUILD-OPTIONS > "$R$(pwd)/GIT-BUILD-OPTIONS"
+for cmd in git $BB;do 
+	ldd $cmd | grep '/' | sed 's,.*\s\(/[^ ]*\).*,\1,' | while read i; do
+		mkdir -p "$R$(dirname $i)"
+		cp "$i" "$R/$i"
+	done
 done
-echo "Execute this in root: 'chroot $R /bin/su - $(id -nu)'"
+cat <<EOF
+All is set up in $R, execute t1509 with the following commands:
+
+sudo chroot $R /bin/su - $(id -nu)
+IKNOWWHATIAMDOING=YES ./t1509-root-worktree.sh -v -i
+
+When you are done, simply delete $R to clean up
+EOF
-- 
2.3.0.rc1.137.g477eb31