ok op@

Simplify some phrasing, explain what preconditions `got patch' has and what happens to the work tree when an error occurs.

Don't allow `got patch' to delete files that are not known, or add files that are already known and to edit files that are known, not obstructed and without conflicts.

These commands perform potentially long-running operations on the repository after reading information from the work tree. There is no need for them to keep the work tree locked until the end. Doing so blocks other commands the user may want to run concurrently. For example, the user may want to be able to run 'got diff' in the work tree while browsing 'got log' output in less(1). Pointed out by Misha on gameoftrees IRC.

add two helper functions (schedule_add, schedule_del) and move the guts of apply_patch into a new function `patch_file'. This simplifies apply_patch and makes easier to figure out what happens. Then, drop GOT_ERR_PATCH_PATHS_DIFFER since we allow the to rename files.

otherwise got-read-patch can't parse any patch because the position indicator is at the end of file. While here fix the return too and set patchfd to -1 on error (stsp suggestion.) ok thomas, stsp

ok thomas, stsp

Use got_repo_match_object_id() instead of hand-rolled code and pick up the updated handling of reference arguments. ok stsp

This was a leftover from got_repo_resolve_commit_arg() which was superseded in commit 71a276322e39e17baf5697b5daac8e8fe6ad2ae1