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
cat > makepatch.py <<EOF
f = file('eol.diff', 'wb')
w = f.write
w('test message\n')
w('diff --git a/a b/a\n')
w('--- a/a\n')
w('+++ b/a\n')
w('@@ -1,5 +1,5 @@\n')
w(' a\n')
w('-bbb\r\n')
w('+yyyy\r\n')
w(' cc\r\n')
w(' \n')
w(' d\n')
w('-e\n')
w('\ No newline at end of file\n')
w('+z\r\n')
w('\ No newline at end of file\r\n')
EOF
hg init repo
cd repo
echo '\.diff' > .hgignore
# Test different --eol values
python -c 'file("a", "wb").write("a\nbbb\ncc\n\nd\ne")'
hg ci -Am adda
python ../makepatch.py
echo % invalid eol
hg --config patch.eol='LFCR' import eol.diff
hg revert -a
echo % force LF
hg --traceback --config patch.eol='LF' import eol.diff
python -c 'print repr(file("a","rb").read())'
hg st
echo % force CRLF
hg up -C 0
hg --traceback --config patch.eol='CRLF' import eol.diff
python -c 'print repr(file("a","rb").read())'
hg st
echo % auto EOL on LF file
hg up -C 0
hg --traceback --config patch.eol='auto' import eol.diff
python -c 'print repr(file("a","rb").read())'
hg st
echo % auto EOL on CRLF file
python -c 'file("a", "wb").write("a\r\nbbb\r\ncc\r\n\r\nd\r\ne")'
hg commit -m 'switch EOLs in a'
hg --traceback --config patch.eol='auto' import eol.diff
python -c 'print repr(file("a","rb").read())'
hg st
echo % auto EOL on new file or source without any EOL
python -c 'file("noeol", "wb").write("noeol")'
hg add noeol
hg commit -m 'add noeol'
python -c 'file("noeol", "wb").write("noeol\r\nnoeol\n")'
python -c 'file("neweol", "wb").write("neweol\nneweol\r\n")'
hg add neweol
hg diff --git > noeol.diff
hg revert --no-backup noeol neweol
rm neweol
hg --traceback --config patch.eol='auto' import -m noeol noeol.diff
python -c 'print repr(file("noeol","rb").read())'
python -c 'print repr(file("neweol","rb").read())'
hg st
# Test --eol and binary patches
python -c 'file("b", "wb").write("a\x00\nb\r\nd")'
hg ci -Am addb
python -c 'file("b", "wb").write("a\x00\nc\r\nd")'
hg diff --git > bin.diff
hg revert --no-backup b
echo % binary patch with --eol
hg import --config patch.eol='CRLF' -m changeb bin.diff
python -c 'print repr(file("b","rb").read())'
hg st
cd ..