view tests/test-churn @ 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

echo "[extensions]" >> $HGRCPATH
echo "churn=" >> $HGRCPATH

echo % create test repository
hg init repo
cd repo
echo a > a
hg ci -Am adda -u user1 -d 6:00
echo b >> a
echo b > b
hg ci -m changeba -u user2 -d 9:00 a
hg ci -Am addb -u user2 -d 9:30
echo c >> a
echo c >> b
echo c > c
hg ci -m changeca -u user3 -d 12:00 a
hg ci -m changecb -u user3 -d 12:15 b
hg ci -Am addc -u user3 -d 12:30
mkdir -p d/e
echo abc > d/e/f1.txt
hg ci -Am "add d/e/f1.txt" -u user1 -d 12:45 d/e/f1.txt
mkdir -p d/g
echo def > d/g/f2.txt
hg ci -Am "add d/g/f2.txt" -u user1 -d 13:00 d/g/f2.txt

echo % churn separate directories
cd d
hg churn e
echo % churn all
hg churn
echo % churn excluding one dir
hg churn -X e
echo % churn up to rev 2
hg churn -r :2
cd ..
echo % churn with aliases
cat > ../aliases <<EOF
user1 alias1
user3 alias3
EOF
hg churn --aliases ../aliases
echo % churn with .hgchurn
mv ../aliases .hgchurn
hg churn
rm .hgchurn
echo % churn with column specifier
COLUMNS=40 hg churn
echo % churn by hour
hg churn -f '%H' -s

echo % churn with separated added/removed lines
hg rm d/g/f2.txt
hg ci -Am "removed d/g/f2.txt" -u user1 -d 14:00 d/g/f2.txt
hg churn --diffstat
echo % churn --diffstat with color
hg --config extensions.color= churn --config color.mode=ansi \
    --diffstat --color=always

echo % changeset number churn
hg churn -c

echo 'with space = no-space' >> ../aliases
echo a >> a
hg commit -m a -u 'with space' -d 15:00
echo % churn with space in alias
hg churn --aliases ../aliases -r tip

cd ..

# issue 833: ZeroDivisionError
hg init issue-833
cd issue-833
touch foo
hg ci -Am foo
# this was failing with a ZeroDivisionError
hg churn
cd ..