This makes the index iterator honor the GIT_ITERATOR_IGNORE_CASE and GIT_ITERATOR_DONT_IGNORE_CASE flags without modifying the index data itself. To take advantage of this, I had to export a number of the internal index entry comparison functions. I also wrote some new tests to exercise the capability.
This is just laying some groundwork for internal index changes that I'm working on.
Don't lose our elements when calling git_vector_set()
This improvement the management of the lock around submodule cache updates slightly, using the lock to make sure that foreach can safely make a snapshot of all existing submodules and making sure that git_submodule_add_setup also grabs a lock before inserting the new submodule. Cache initialization / refresh should already have been holding the lock correctly as it adds submodules.
This updates the git_pqueue to simply be a set of specialized init/insert/pop functions on a git_vector. To preserve the pqueue feature of having a fixed size heap, I converted the "sorted" field in git_vectors to a more general "flags" field so that pqueue could mix in it's own flag. This had a bunch of ramifications because a number of places were directly looking at the vector "sorted" field - I added a couple new git_vector helpers (is_sorted, set_sorted) so the specific representation of this information could be abstracted.
This renames git_vector_free_all to the better git_vector_free_deep and also contains a couple of memory leak fixes based on valgrind checks. The fixes are specifically: failure to free global dir path variables when not compiled with threading on and failure to free filters from the filter registry that had not be initialized fully.
This changes the behavior of callbacks so that the callback error code is not converted into GIT_EUSER and instead we propagate the return value through to the caller. Instead of using the giterr_capture and giterr_restore functions, we now rely on all functions to pass back the return value from a callback. To avoid having a return value with no error message, the user can call the public giterr_set_str or some such function to set an error message. There is a new helper 'giterr_set_callback' that functions can invoke after making a callback which ensures that some error message was set in case the callback did not set one. In places where the sign of the callback return value is meaningful (e.g. positive to skip, negative to abort), only the negative values are returned back to the caller, obviously, since the other values allow for continuing the loop. The hardest parts of this were in the checkout code where positive return values were overloaded as meaningful values for checkout. I fixed this by adding an output parameter to many of the internal checkout functions and removing the overload. This added some code, but it is probably a better implementation. There is some funkiness in the network code where user provided callbacks could be returning a positive or a negative value and we want to rely on that to cancel the loop. There are still a couple places where an user error might get turned into GIT_EUSER there, I think, though none exercised by the tests.
There are a lot of places that we call git__free on each item in a vector and then call git_vector_free on the vector itself. This just wraps that up into one convenient helper function.