b6d8f309 (diff-raw format update take #2., 2005-05-23) started
documenting the diff format, and it said
...
(8) sha1 for "dst"; 0{40} if creation, unmerged or "look at work tree".
(9) status, followed by similarlity index number only for C and R.
(10) a tab or a NUL when '-z' option is used.
...
because C and R _were_ the only ones that came with a number back
then. This was corrected by ddafa7e9 (diff-helper: Fix R/C score
parsing under -z flag., 2005-05-29) and we started saying "score"
instead of "similarlity index" (because we can have other kind of
score there), and stopped saying "only for C and R" (because Git is
an ever evolving system). Later f345b0a0 (Add -B flag to diff-*
brothers., 2005-05-30) introduced a new concept, "dissimilarity"
score; it did not have to fix any documentation.
The current text that says only C and R can have scores came
independently from a5a323f3 (Add reference for status letters in
documentation., 2008-11-02) and it was wrong from the day one.
Noticed-by: Mike Hommey
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/dotgit-case-maint-1.8.5:
is_hfs_dotgit: loosen over-eager match of \u{..47}
Our is_hfs_dotgit function relies on the hackily-implemented
next_hfs_char to give us the next character that an HFS+
filename comparison would look at. It's hacky because it
doesn't implement the full case-folding table of HFS+; it
gives us just enough to see if the path matches ".git".
At the end of next_hfs_char, we use tolower() to convert our
32-bit code point to lowercase. Our tolower() implementation
only takes an 8-bit char, though; it throws away the upper
24 bits. This means we can't have any false negatives for
is_hfs_dotgit. We only care about matching 7-bit ASCII
characters in ".git", and we will correctly process 'G' or
'g'.
However, we _can_ have false positives. Because we throw
away the upper bits, code point \u{0147} (for example) will
look like 'G' and get downcased to 'g'. It's not known
whether a sequence of code points whose truncation ends up
as ".git" is meaningful in any language, but it does not
hurt to be more accurate here. We can just pass out the full
32-bit code point, and compare it manually to the upper and
lowercase characters we care about.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* dotgit-case-maint-1.8.5: fsck: complain about NTFS ".git" aliases in trees read-cache: optionally disallow NTFS .git variants path: add is_ntfs_dotgit() helper fsck: complain about HFS+ ".git" aliases in trees read-cache: optionally disallow HFS+ .git variants utf8: add is_hfs_dotgit() helper fsck: notice .git case-insensitively t1450: refactor ".", "..", and ".git" fsck tests verify_dotfile(): reject .git case-insensitively read-tree: add tests for confusing paths like ".." and ".git" unpack-trees: propagate errors adding entries to the index
Now that the index can block pathnames that can be mistaken to mean ".git" on NTFS and FAT32, it would be helpful for fsck to notice such problematic paths. This lets servers which use receive.fsckObjects block them before the damage spreads. Note that the fsck check is always on, even for systems without core.protectNTFS set. This is technically more restrictive than we need to be, as a set of users on ext4 could happily use these odd filenames without caring about NTFS. However, on balance, it's helpful for all servers to block these (because the paths can be used for mischief, and servers which bother to fsck would want to stop the spread whether they are on NTFS themselves or not), and hardly anybody will be affected (because the blocked names are variants of .git or git~1, meaning mischief is almost certainly what the tree author had in mind). Ideally these would be controlled by a separate "fsck.protectNTFS" flag. However, it would be much nicer to be able to enable/disable _any_ fsck flag individually, and any scheme we choose should match such a system. Given the likelihood of anybody using such a path in practice, it is not unreasonable to wait until such a system materializes. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of disallowing ".git" in the index is that we
would never want to accidentally overwrite files in the
repository directory. But this means we need to respect the
filesystem's idea of when two paths are equal. The prior
commit added a helper to make such a comparison for NTFS
and FAT32; let's use it in verify_path().
We make this check optional for two reasons:
1. It restricts the set of allowable filenames, which is
unnecessary for people who are not on NTFS nor FAT32.
In practice this probably doesn't matter, though, as
the restricted names are rather obscure and almost
certainly would never come up in practice.
2. It has a minor performance penalty for every path we
insert into the index.
This patch ties the check to the core.protectNTFS config
option. Though this is expected to be most useful on Windows,
we allow it to be set everywhere, as NTFS may be mounted on
other platforms. The variable does default to on for Windows,
though.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not allow paths with a ".git" component to be added to
the index, as that would mean repository contents could
overwrite our repository files. However, asking "is this
path the same as .git" is not as simple as strcmp() on some
filesystems.
On NTFS (and FAT32), there exist so-called "short names" for
backwards-compatibility: 8.3 compliant names that refer to the same files
as their long names. As ".git" is not an 8.3 compliant name, a short name
is generated automatically, typically "git~1".
Depending on the Windows version, any combination of trailing spaces and
periods are ignored, too, so that both "git~1." and ".git." still refer
to the Git directory. The reason is that 8.3 stores file names shorter
than 8 characters with trailing spaces. So literally, it does not matter
for the short name whether it is padded with spaces or whether it is
shorter than 8 characters, it is considered to be the exact same.
The period is the separator between file name and file extension, and
again, an empty extension consists just of spaces in 8.3 format. So
technically, we would need only take care of the equivalent of this
regex:
(\.git {0,4}|git~1 {0,3})\. {0,3}
However, there are indications that at least some Windows versions might
be more lenient and accept arbitrary combinations of trailing spaces and
periods and strip them out. So we're playing it real safe here. Besides,
there can be little doubt about the intention behind using file names
matching even the more lenient pattern specified above, therefore we
should be fine with disallowing such patterns.
Extra care is taken to catch names such as '.\\.git\\booh' because the
backslash is marked as a directory separator only on Windows, and we want
to use this new helper function also in fsck on other platforms.
A big thank you goes to Ed Thomson and an unnamed Microsoft engineer for
the detailed analysis performed to come up with the corresponding fixes
for libgit2.
This commit adds a function to detect whether a given file name can refer
to the Git directory by mistake.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the index can block pathnames that case-fold to ".git" on HFS+, it would be helpful for fsck to notice such problematic paths. This lets servers which use receive.fsckObjects block them before the damage spreads. Note that the fsck check is always on, even for systems without core.protectHFS set. This is technically more restrictive than we need to be, as a set of users on ext4 could happily use these odd filenames without caring about HFS+. However, on balance, it's helpful for all servers to block these (because the paths can be used for mischief, and servers which bother to fsck would want to stop the spread whether they are on HFS+ themselves or not), and hardly anybody will be affected (because the blocked names are variants of .git with invisible Unicode code-points mixed in, meaning mischief is almost certainly what the tree author had in mind). Ideally these would be controlled by a separate "fsck.protectHFS" flag. However, it would be much nicer to be able to enable/disable _any_ fsck flag individually, and any scheme we choose should match such a system. Given the likelihood of anybody using such a path in practice, it is not unreasonable to wait until such a system materializes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of disallowing ".git" in the index is that we
would never want to accidentally overwrite files in the
repository directory. But this means we need to respect the
filesystem's idea of when two paths are equal. The prior
commit added a helper to make such a comparison for HFS+;
let's use it in verify_path.
We make this check optional for two reasons:
1. It restricts the set of allowable filenames, which is
unnecessary for people who are not on HFS+. In practice
this probably doesn't matter, though, as the restricted
names are rather obscure and almost certainly would
never come up in practice.
2. It has a minor performance penalty for every path we
insert into the index.
This patch ties the check to the core.protectHFS config
option. Though this is expected to be most useful on OS X,
we allow it to be set everywhere, as HFS+ may be mounted on
other platforms. The variable does default to on for OS X,
though.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>