tests/test-symlink-basic

verify: fix "missing revlog!" errors for revlog format v0 and add test

With revlog format v0 the .d files are empty if the only revision stored is an
empty file. Since Mercurial can no longer create format v0 repositories, but
still use it, add a script which creates a repository with a single empty file.
This can be used in other tests if wanted.

#!/bin/sh

"$TESTDIR/hghave" symlink || exit 80

hg init a
cd a
ln -s nothing dangling
hg commit -m 'commit symlink without adding' dangling
hg add dangling
hg commit -m 'add symlink'

hg tip -v
hg manifest --debug
echo '% rev 0:'
$TESTDIR/readlink.py dangling

rm dangling
ln -s void dangling
hg commit -m 'change symlink'
echo '% rev 1:'
$TESTDIR/readlink.py dangling

echo '% modifying link'
rm dangling
ln -s empty dangling
$TESTDIR/readlink.py dangling

echo '% reverting to rev 0:'
hg revert -r 0 -a
$TESTDIR/readlink.py dangling

echo '% backups:'
$TESTDIR/readlink.py *.orig

rm *.orig
hg up -C
echo '% copies'
hg cp -v dangling dangling2
hg st -Cmard
$TESTDIR/readlink.py dangling dangling2

echo '% issue995'
hg up -C
mkdir dir
ln -s dir dirlink
hg ci -qAm 'add dirlink'
mkdir newdir
mv dir newdir/dir
mv dirlink newdir/dirlink
hg mv -A dirlink newdir/dirlink