git-commit-vandalism/t/t3910-mac-os-precompose.sh

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git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
#!/bin/sh
#
# Copyright (c) 2012 Torsten Bögershausen
#
test_description='utf-8 decomposed (nfd) converted to precomposed (nfc)'
. ./test-lib.sh
if ! test_have_prereq UTF8_NFD_TO_NFC
then
skip_all="filesystem does not corrupt utf-8"
test_done
fi
# create utf-8 variables
Adiarnfc=$(printf '\303\204')
Adiarnfd=$(printf 'A\314\210')
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
Odiarnfc=$(printf '\303\226')
Odiarnfd=$(printf 'O\314\210')
AEligatu=$(printf '\303\206')
Invalidu=$(printf '\303\377')
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
#Create a string with 255 bytes (decomposed)
Alongd=$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd #21 Byte
Alongd=$Alongd$Alongd$Alongd #63 Byte
Alongd=$Alongd$Alongd$Alongd$Alongd$Adiarnfd #255 Byte
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
#Create a string with 254 bytes (precomposed)
Alongc=$AEligatu$AEligatu$AEligatu$AEligatu$AEligatu #10 Byte
Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc #50 Byte
Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc #250 Byte
Alongc=$Alongc$AEligatu$AEligatu #254 Byte
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
test_expect_success "detect if nfd needed" '
precomposeunicode=$(git config core.precomposeunicode) &&
test "$precomposeunicode" = true &&
git config core.precomposeunicode true
'
test_expect_success "setup" '
>x &&
git add x &&
git commit -m "1st commit" &&
git rm x &&
git commit -m "rm x"
'
test_expect_success "setup case mac" '
git checkout -b mac_os
'
# This will test nfd2nfc in git diff
test_expect_success "git diff f.Adiar" '
touch f.$Adiarnfc &&
git add f.$Adiarnfc &&
echo f.Adiarnfc >f.$Adiarnfc &&
git diff f.$Adiarnfd >expect &&
git diff f.$Adiarnfc >actual &&
test_cmp expect actual &&
git reset HEAD f.Adiarnfc &&
rm f.$Adiarnfc expect actual
'
# This will test nfd2nfc in git diff-files
test_expect_success "git diff-files f.Adiar" '
touch f.$Adiarnfc &&
git add f.$Adiarnfc &&
echo f.Adiarnfc >f.$Adiarnfc &&
git diff-files f.$Adiarnfd >expect &&
git diff-files f.$Adiarnfc >actual &&
test_cmp expect actual &&
git reset HEAD f.Adiarnfc &&
rm f.$Adiarnfc expect actual
'
# This will test nfd2nfc in git diff-index
test_expect_success "git diff-index f.Adiar" '
touch f.$Adiarnfc &&
git add f.$Adiarnfc &&
echo f.Adiarnfc >f.$Adiarnfc &&
git diff-index HEAD f.$Adiarnfd >expect &&
git diff-index HEAD f.$Adiarnfc >actual &&
test_cmp expect actual &&
git reset HEAD f.Adiarnfc &&
rm f.$Adiarnfc expect actual
'
# This will test nfd2nfc in readdir()
test_expect_success "add file Adiarnfc" '
echo f.Adiarnfc >f.$Adiarnfc &&
git add f.$Adiarnfc &&
git commit -m "add f.$Adiarnfc"
'
# This will test nfd2nfc in git diff-tree
test_expect_success "git diff-tree f.Adiar" '
echo f.Adiarnfc >>f.$Adiarnfc &&
git diff-tree HEAD f.$Adiarnfd >expect &&
git diff-tree HEAD f.$Adiarnfc >actual &&
test_cmp expect actual &&
git checkout f.$Adiarnfc &&
rm expect actual
'
# This will test nfd2nfc in git stage()
test_expect_success "stage file d.Adiarnfd/f.Adiarnfd" '
mkdir d.$Adiarnfd &&
echo d.$Adiarnfd/f.$Adiarnfd >d.$Adiarnfd/f.$Adiarnfd &&
git stage d.$Adiarnfd/f.$Adiarnfd &&
git commit -m "add d.$Adiarnfd/f.$Adiarnfd"
'
test_expect_success "add link Adiarnfc" '
ln -s d.$Adiarnfd/f.$Adiarnfd l.$Adiarnfc &&
git add l.$Adiarnfc &&
git commit -m "add l.Adiarnfc"
'
# This will test git log
test_expect_success "git log f.Adiar" '
git log f.$Adiarnfc > f.Adiarnfc.log &&
git log f.$Adiarnfd > f.Adiarnfd.log &&
test -s f.Adiarnfc.log &&
test -s f.Adiarnfd.log &&
test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
rm f.Adiarnfc.log f.Adiarnfd.log
'
# This will test git ls-files
test_expect_success "git lsfiles f.Adiar" '
git ls-files f.$Adiarnfc > f.Adiarnfc.log &&
git ls-files f.$Adiarnfd > f.Adiarnfd.log &&
test -s f.Adiarnfc.log &&
test -s f.Adiarnfd.log &&
test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
rm f.Adiarnfc.log f.Adiarnfd.log
'
# This will test git mv
test_expect_success "git mv" '
git mv f.$Adiarnfd f.$Odiarnfc &&
git mv d.$Adiarnfd d.$Odiarnfc &&
git mv l.$Adiarnfd l.$Odiarnfc &&
git commit -m "mv Adiarnfd Odiarnfc"
'
# Files can be checked out as nfc
# And the link has been corrected from nfd to nfc
test_expect_success "git checkout nfc" '
rm f.$Odiarnfc &&
git checkout f.$Odiarnfc
'
# Make it possible to checkout files with their NFD names
test_expect_success "git checkout file nfd" '
rm -f f.* &&
git checkout f.$Odiarnfd
'
# Make it possible to checkout links with their NFD names
test_expect_success "git checkout link nfd" '
rm l.* &&
git checkout l.$Odiarnfd
'
test_expect_success "setup case mac2" '
git checkout master &&
git reset --hard &&
git checkout -b mac_os_2
'
# This will test nfd2nfc in git commit
test_expect_success "commit file d2.Adiarnfd/f.Adiarnfd" '
mkdir d2.$Adiarnfd &&
echo d2.$Adiarnfd/f.$Adiarnfd >d2.$Adiarnfd/f.$Adiarnfd &&
git add d2.$Adiarnfd/f.$Adiarnfd &&
git commit -m "add d2.$Adiarnfd/f.$Adiarnfd" -- d2.$Adiarnfd/f.$Adiarnfd
'
test_expect_success "setup for long decomposed filename" '
git checkout master &&
git reset --hard &&
git checkout -b mac_os_long_nfd_fn
'
test_expect_success "Add long decomposed filename" '
echo longd >$Alongd &&
git add * &&
git commit -m "Long filename"
'
test_expect_success "setup for long precomposed filename" '
git checkout master &&
git reset --hard &&
git checkout -b mac_os_long_nfc_fn
'
test_expect_success "Add long precomposed filename" '
echo longc >$Alongc &&
git add * &&
git commit -m "Long filename"
'
t3910: show failure of core.precomposeunicode with decomposed filenames If you have existing decomposed filenames in your git repository (e.g., that were created with older versions of git that did not precompose unicode), a modern git with core.precomposeunicode set does not handle them well. The problem is that we normalize the paths coming from the disk into their precomposed form, and then compare them against the literal bytes in the index. This makes things better if you have the precomposed form in the index. It makes things worse if you actually have the decomposed form in the index. As a result, paths with decomposed filenames may have their precomposed variants listed as untracked files (even though the precomposed variants do not exist on-disk at all). This patch just adds a test to demonstrate the breakage. Some possible fixes are: 1. Tell everyone that NFD in the git repo is wrong, and they should make a new commit to normalize all their in-repo files to be precomposed. This is probably not the right thing to do, because it still doesn't fix checkouts of old history. And it spreads the problem to people on byte-preserving filesystems (like ext4), because now they have to start precomposing their filenames as they are adde to git. 2. Do all index filename comparisons using a UTF-8 aware comparison function when core.precomposeunicode is set. This would probably have bad performance, and somewhat defeats the point of converting the filenames at the readdir level in the first place. 3. Convert index filenames to their precomposed form when we read the index from disk. This would be efficient, but we would have to be careful not to write the precomposed forms back out to disk. 4. Introduce some infrastructure to efficiently match up the precomposed/decomposed forms. We already do something similar for case-insensitive files using name-hash.c. We might be able to adapt that strategy here. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-28 18:16:31 +02:00
test_expect_failure 'handle existing decomposed filenames' '
echo content >"verbatim.$Adiarnfd" &&
git -c core.precomposeunicode=false add "verbatim.$Adiarnfd" &&
git commit -m "existing decomposed file" &&
git ls-files --exclude-standard -o "verbatim*" >untracked &&
test_must_be_empty untracked
t3910: show failure of core.precomposeunicode with decomposed filenames If you have existing decomposed filenames in your git repository (e.g., that were created with older versions of git that did not precompose unicode), a modern git with core.precomposeunicode set does not handle them well. The problem is that we normalize the paths coming from the disk into their precomposed form, and then compare them against the literal bytes in the index. This makes things better if you have the precomposed form in the index. It makes things worse if you actually have the decomposed form in the index. As a result, paths with decomposed filenames may have their precomposed variants listed as untracked files (even though the precomposed variants do not exist on-disk at all). This patch just adds a test to demonstrate the breakage. Some possible fixes are: 1. Tell everyone that NFD in the git repo is wrong, and they should make a new commit to normalize all their in-repo files to be precomposed. This is probably not the right thing to do, because it still doesn't fix checkouts of old history. And it spreads the problem to people on byte-preserving filesystems (like ext4), because now they have to start precomposing their filenames as they are adde to git. 2. Do all index filename comparisons using a UTF-8 aware comparison function when core.precomposeunicode is set. This would probably have bad performance, and somewhat defeats the point of converting the filenames at the readdir level in the first place. 3. Convert index filenames to their precomposed form when we read the index from disk. This would be efficient, but we would have to be careful not to write the precomposed forms back out to disk. 4. Introduce some infrastructure to efficiently match up the precomposed/decomposed forms. We already do something similar for case-insensitive files using name-hash.c. We might be able to adapt that strategy here. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-28 18:16:31 +02:00
'
# Test if the global core.precomposeunicode stops autosensing
# Must be the last test case
test_expect_success "respect git config --global core.precomposeunicode" '
git config --global core.precomposeunicode true &&
rm -rf .git &&
git init &&
precomposeunicode=$(git config core.precomposeunicode) &&
test "$precomposeunicode" = "true"
'
git on Mac OS and precomposed unicode Mac OS X mangles file names containing unicode on file systems HFS+, VFAT or SAMBA. When a file using unicode code points outside ASCII is created on a HFS+ drive, the file name is converted into decomposed unicode and written to disk. No conversion is done if the file name is already decomposed unicode. Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same result as open("\x41\xcc\x88",...) with a decomposed "Ä". As a consequence, readdir() returns the file names in decomposed unicode, even if the user expects precomposed unicode. Unlike on HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in precomposed unicode, but readdir() still returns file names in decomposed unicode. When a git repository is stored on a network share using SAMBA, file names are send over the wire and written to disk on the remote system in precomposed unicode, but Mac OS X readdir() returns decomposed unicode to be compatible with its behaviour on HFS+ and VFAT. The unicode decomposition causes many problems: - The names "git add" and other commands get from the end user may often be precomposed form (the decomposed form is not easily input from the keyboard), but when the commands read from the filesystem to see what it is going to update the index with already is on the filesystem, readdir() will give decomposed form, which is different. - Similarly "git log", "git mv" and all other commands that need to compare pathnames found on the command line (often but not always precomposed form; a command line input resulting from globbing may be in decomposed) with pathnames found in the tree objects (should be precomposed form to be compatible with other systems and for consistency in general). - The same for names stored in the index, which should be precomposed, that may need to be compared with the names read from readdir(). NFS mounted from Linux is fully transparent and does not suffer from the above. As Mac OS X treats precomposed and decomposed file names as equal, we can - wrap readdir() on Mac OS X to return the precomposed form, and - normalize decomposed form given from the command line also to the precomposed form, to ensure that all pathnames used in Git are always in the precomposed form. This behaviour can be requested by setting "core.precomposedunicode" configuration variable to true. The code in compat/precomposed_utf8.c implements basically 4 new functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(), precomposed_utf8_closedir() and precompose_argv(). The first three are to wrap opendir(3), readdir(3), and closedir(3) functions. The argv[] conversion allows to use the TAB filename completion done by the shell on command line. It tolerates other tools which use readdir() to feed decomposed file names into git. When creating a new git repository with "git init" or "git clone", "core.precomposedunicode" will be set "false". The user needs to activate this feature manually. She typically sets core.precomposedunicode to "true" on HFS and VFAT, or file systems mounted via SAMBA. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 15:50:25 +02:00
test_done