There can be a significant difference between the system where we created the buffer (if at all) and when the caller provides us with the contents of a commit. Provide some test cases (we have to adapt the existing ones because they refer to trees and commits which do not exist).
Move to the `git_error` name in the internal API for error-related functions.
Update internal usage to use the `git_reference` names for constants.
Use the new object_type enumeration names within the codebase.
When parsing a signature's timezone offset, we first check whether there is a timezone at all by verifying that there are still bytes left to read following the time itself. The check thus looks like `time_end + 1 < buffer_end`, which is actually correct in this case. After setting the timezone's start pointer to that location, we compute the remaining bytes by using the formula `buffer_end - tz_start + 1`, re-using the previous `time_end + 1`. But this is in fact missing the braces around `(tz_start + 1)`, thus leading to an overestimation of the remaining bytes by a length of two. In case of a non-NUL terminated buffer, this will result in an overflow. The function `git_signature__parse` is only used in two locations. First is `git_signature_from_buffer`, which only accepts a string without a length. The string thus necessarily has to be NUL terminated and cannot trigger the issue. The other function is `git_commit__parse_raw`, which can in fact trigger the error as it may receive non-NUL terminated commit data. But as objects read from the ODB are always NUL-terminated by us as a cautionary measure, it cannot trigger the issue either. In other words, this error does not have any impact on security.
C++ style comment ("//") are not specified by the ISO C90 standard and
thus do not conform to it. While libgit2 aims to conform to C90, we did
not enforce it until now, which is why quite a lot of these
non-conforming comments have snuck into our codebase. Do a tree-wide
conversion of all C++ style comments to the supported C style comments
to allow us enforcing strict C90 compliance in a later commit.
Git considers '-0000' a valid offset for signature lines. They need to be treated as _not_ equal to a '+0000' signature offset. Parsing a signature line stores the offset in a signed integer which does not distinguish between `+0` and `-0`. This patch adds an additional flag `sign` to the `git_time` in the `signature` object which is populated with the sign of the offset. In addition to exposing this information to the user, this information is also used to compare signatures. /cc @pks-t @ethomson
`test_commit_commit__create_initial_commit_parent_not_current` was not correctly testing that `HEAD` was not changed. Now we grab the oid that it was pointing to before the call to `git_commit_create` and the oid that it's pointing to afterwards and compare those.