view tests/test-git-export @ 11769:ca6cebd8734e stable

dirstate: ignore symlinks when fs cannot handle them (issue1888)

When the filesystem cannot handle the executable bit, we currently
ignore it completely when looking for modified files. Similarly, it is
impossible to set or clear the bit when the filesystem ignores it.

This patch makes Mercurial treat symbolic links the same way.

Symlinks are a little different since they manifest themselves as
small files containing a filename (the symlink target). On Windows,
these files show up as regular files, and on Linux and Mac they show
up as real symlinks.

Issue1888 presents a case where the symlink files are better ignored
from the Windows side. A Linux client creates symlinks in a working
copy which is shared over a network between Linux and Windows clients.

The Samba server is helpful and defererences the symlink when the
Windows client looks at it. This means that Mercurial on the Windows
side sees file content instead of a file name in the symlink, and
hence flags the link as modified. Ignoring the change would be much
more helpful, similarly to how Mercurial does not report any changes
when executable bits are ignored in a checkout on Windows.

An initial checkout of a symbolic link on a file system that cannot
handle symbolic links will still result in a regular file containing
the target file name as its content. Sharing such a checkout with a
Linux client will not turn the file into a symlink automatically, but
'hg revert' can fix that. After the revert, the Windows client will
see the correct file content (provided by the Samba server when it
follows the link on the Linux side) and otherwise ignore the change.

Running 'hg perfstatus' 10 times gives these results:

  Before:          After:
  min: 0.544703    min: 0.546549
  med: 0.547592    med: 0.548881
  avg: 0.549146    avg: 0.548549
  max: 0.564112    max: 0.551504

The median time is increased about 0.24%.

#!/bin/sh

hg init a
cd a

echo start > start
hg ci -Amstart
echo new > new
hg ci -Amnew
echo '% new file'
hg diff --git -r 0

hg cp new copy
hg ci -mcopy
echo '% copy'
hg diff --git -r 1:tip

hg mv copy rename
hg ci -mrename
echo '% rename'
hg diff --git -r 2:tip

hg rm rename
hg ci -mdelete
echo '% delete'
hg diff --git -r 3:tip

cat > src <<EOF
1
2
3
4
5
EOF
hg ci -Amsrc
chmod +x src
hg ci -munexec
echo '% chmod 644'
hg diff --git -r 5:tip

hg mv src dst
chmod -x dst
echo a >> dst
hg ci -mrenamemod
echo '% rename+mod+chmod'
hg diff --git -r 6:tip

echo '% nonexistent in tip+chmod'
hg diff --git -r 5:6

echo '% binary diff'
cp $TESTDIR/binfile.bin .
hg add binfile.bin
hg diff --git > b.diff
cat b.diff

echo '% import binary diff'
hg revert binfile.bin
rm binfile.bin
hg import -mfoo b.diff
cmp binfile.bin $TESTDIR/binfile.bin

echo
echo '% rename binary file'
hg mv binfile.bin renamed.bin
hg diff --git

echo
echo '% diff across many revisions'
hg mv dst dst2
hg ci -m 'mv dst dst2'

echo >> start
hg ci -m 'change start'

hg revert -r -2 start
hg mv dst2 dst3
hg ci -m 'mv dst2 dst3; revert start'

hg diff --git -r 9:11
echo '%  reversed'
hg diff --git -r 11:9

echo a >> foo
hg add foo
hg ci -m 'add foo'
echo b >> foo
hg ci -m 'change foo'
hg mv foo bar
hg ci -m 'mv foo bar'
echo c >> bar
hg ci -m 'change bar'

echo
echo '% file created before r1 and renamed before r2'
hg diff --git -r -3:-1
echo '%  reversed'
hg diff --git -r -1:-3
echo
echo '% file created in r1 and renamed before r2'
hg diff --git -r -4:-1
echo '%  reversed'
hg diff --git -r -1:-4
echo
echo '% file created after r1 and renamed before r2'
hg diff --git -r -5:-1
echo '%  reversed'
hg diff --git -r -1:-5

echo
echo '% comparing with the working dir'
echo >> start
hg ci -m 'change start again'

echo > created
hg add created
hg ci -m 'add created'

hg mv created created2
hg ci -m 'mv created created2'

hg mv created2 created3
echo "% there's a copy in the working dir..."
hg diff --git
echo
echo "% ...but there's another copy between the original rev and the wd"
hg diff --git -r -2
echo
echo "% ...but the source of the copy was created after the original rev"
hg diff --git -r -3
hg ci -m 'mv created2 created3'

echo > brand-new
hg add brand-new
hg ci -m 'add brand-new'
hg mv brand-new brand-new2
echo '% created in parent of wd; renamed in the wd'
hg diff --git

echo
echo '% created between r1 and parent of wd; renamed in the wd'
hg diff --git -r -2
hg ci -m 'mv brand-new brand-new2'

echo '% one file is copied to many destinations and removed'
hg cp brand-new2 brand-new3
hg mv brand-new2 brand-new3-2
hg ci -m 'multiple renames/copies'
hg diff --git -r -2 -r -1
echo '%  reversed'
hg diff --git -r -1 -r -2

echo '% there should be a trailing TAB if there are spaces in the file name'
echo foo > 'with spaces'
hg add 'with spaces'
hg diff --git
hg ci -m 'add filename with spaces'