In looking at PR #878, I found a few small bugs in the diff code,
mostly related to work that can be avoided when processing tree-
to-tree diffs that was always being carried out. This commit has
some small fixes in it.
This creates a public API for adding to the internal ignores
list, which already existing but was not accessible.
This adds the new default value for core.excludesfile also.
Up to now, the idea was that the user would do all the operations for
one repository in the same thread. Thus we could have the
memory-mapped window information thread-local and avoid any locking.
This is not practical in a few environments, such as Apple's GCD which
allocates threads arbitrarily or the .NET CLR, where the OS-level
thread can change at any moment.
Make the control structure global and protect it with a mutex so we
don't depend on the thread currently executing the code.
If you want to be absolutely safe with git_message_prettify, you
can now pass a NULL pointer for the buffer and get back the number
of bytes that would be copied into the buffer.
This means that an error is a non-negative return code and a
success will be greater than zero from this function.
Returning a negative cancels the walk, and returning a positive one
causes us to skip an entry, which was previously done by a negative
value.
This allows us to stay consistent with the rest of the functions that
take a callback and keeps the skipping functionality.
In the documentation for git_config_get_mapped, the sample mapping
array uses [3] but has 4 entries. Fix by dropping the size entirely and
letting the compiler figure it out.
Commit 0c9eacf3d2 introduced the function
git_attr_value and switched the GIT_ATTR_* macros to use it, but
attempting to use that function leads to a linker error (undefined
reference to `git_attr_value'). Export git_attr_value so programs can
actually call it.
There is a little cleanup necessary from PR #843. Since the
new callbacks return `GIT_EUSER` we have to be a little careful
about return values when they are used internally to the library.
Also, callbacks should be checked for non-zero return values,
not just less than zero.
