Older versions of git would only write peeled entries for
items under refs/tags/. Newer versions will write them for
all refs, and we should be prepared to handle that.
There is an occasional assertion failure in sha1_entry_pos from
pack_entry_find_index when running threaded. Holding the mutex
around the code that grabs the index_map data and processes it
makes this assertion failure go away.
There are many paths through revparse that may return an error
code without reporting an error, I believe. This fixes one of
them. Because of the backtracking in revparse, it is pretty
complicated to fix the others.
A number of places were looking up option config values and then
not clearing the error codes if the values were not found. This
moves the repeated pattern into a shared routine and adds the
extra call to giterr_clear() when needed.
There are some cases, particularly where no loaded ODB backends
support a particular operation, where we would return an error
code without having set an error. This catches those cases and
reports that no ODB backends support the operation in question.
When diff encounters an untracked directory, there was a shortcut
that it took which is not compatible with core git. This makes
the default behavior no longer take that shortcut and instead look
inside the untracked directory to see if there are any untracked
files within it. If there are not, then the directory is treated
as an ignore directory instead of an untracked directory. This
has implications for the git_status APIs.
In preparation for more changes to the internal diff logic, it
seemed wise to split the very large git_diff__from_iterators into
separate functions that handle the four main cases (unmatched old
item, unmatched new item, unmatched new directory, and matched
old and new items). Hopefully this will keep the logic easier to
follow even as more cases have to be added to this code.