libgit2 currently identifies loose objects as corrupt if they've been
deflated using a window size less than 32Kb, because the
is_zlib_compressed_data() function doesn't recognise the header
byte as a zlib header. This patch makes the method tolerant of
all valid window sizes (15-bit to 8-bit) - but doesn't sacrifice
it's accuracy in distingushing the standard loose-object format
from the experimental (now abandoned) format. It's based on a patch
which has been merged into C-Git master branch:
https://github.com/git/git/commit/7f684a2aff636f44a506
On memory constrained systems zlib may use a much smaller window
size - working on Agit, I found that Android uses a 4KB window;
giving a header byte of 0x48, not 0x78. Consequently all loose
objects generated by the Android platform appear 'corrupt' :(
It might appear that this patch changes isStandardFormat() to the
point where it could incorrectly identify the experimental format as
the standard one, but the two criteria (bitmask & checksum) can only
give a false result for an experimental object where both of the
following are true:
1) object size is exactly 8 bytes when uncompressed (bitmask)
2) [single-byte in-pack git type&size header] * 256
+ [1st byte of the following zlib header] % 31 = 0 (checksum)
As it happens, for all possible combinations of valid object type
(1-4) and window bits (0-7), the only time when the checksum will be
divisible by 31 is for 0x1838 - ie object type *1*, a Commit - which,
due the fields all Commit objects must contain, could never be as
small as 8 bytes in size.
Given this, the combination of the two criteria (bitmask & checksum)
always correctly determines the buffer format, and is more tolerant
than the previous version.
References:
Android uses a 4KB window for deflation:
http://android.git.kernel.org/?p=platform/libcore.git;a=blob;f=luni/src/main/native/java_util_zip_Deflater.cpp;h=c0b2feff196e63a7b85d97cf9ae5bb258
Code snippet searching for false positives with the zlib checksum:
https://gist.github.com/1118177
Change-Id: Ifd84cd2bd6b46f087c9984fb4cbd8309f483dec0
Remove a wrong call to git_mwindow_close which caused a segfault if it
ever did run. In that same piece of code, if the LRU was from the
first wiindow in the list in a different file, we didn't update that
list, so the first element had been freed.
Fix these two issues.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
This makes it slightly easier to debug test failures when one test
opens a repo, has a failure, and doesn't get a chance to close it for
the next test. Now, instead of getting no feedback, we at least see
test failure information.
This makes libgit2 more closely match Git, which only checks for
ambiguous pack entries when given short hashes.
Note that the only time this is ever relevant is when a pack has the
same object more than once (it's happened in the wild, I promise).
When trying to find the end of an email, instead of starting at the
beginning of the signature, we start at the end of the name (after the
first '<').
This brings libgit2 more in line with Git's behavior when reading out
existing signatures.
However, note that Git does not allow names like these through the
usual porcelain; instead, it silently strips any '>' characters it
sees.
The v0.99 tag in the Git repo triggers this behavior:
http://git.kernel.org/?p=git/git.git;a=tag;h=d6602ec5194c87b0fc87103ca4d67251c76f233a
Ideally, we'd allow the tag to be instantiated even though the tagger
field is missing, but this at the very least prevents libgit2 from
crashing.
To test this bug, a new repository has been added based on the test
branch in testrepo.git. It contains a "e90810b" tag that looks like
this:
object e90810b8df3e80c413d903f631643c716887138d
type commit
tag e90810b
This is a very simple tag.
This ensures commit->message is always non-NULL, even if the commit
message is empty or consists of only a newline.
One such commit can be found in the wild in the jQuery repository:
25b424134f
Unfortunately, we can't use the function in fetch.c due to chunked
encoding and keep-alive connections.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
Using a different buffer in each function means that some data might
get lost. Store all the data in a buffer in the transport object.
Take this opportunity to use the generic download-pack function.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
Taken mostly from the git transport's version, this can be used by any
transport that takes its pack data from the network.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
It's a bit awkward to run it as an extra step, and HTTP may need to
send the wants list several times.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
As we don't know the length of the message we want to send to the
other end, we send a chunk size before each message. In later
versions, sending the wants might benefit from batching the lines
together.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
Not every request needs a new connection if we're using a keep-alive
connection. Store the HTTP parser, host and port in the transport in
order to have it available in later calls.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
If either CFLAGS is defined or the user passes -DCMAKE_C_FLAGS to
cmake, the variable already contains flags. Don't overwrite them, but
append them to our settings.
Signed-off-by: Carlos Martín Nieto <carlos@cmartin.tk>
