tweak and ok stsp@

Suggested by stsp@. This makes possible to tell if 'got patch' used a merge-base from the repository for the 3-way merge or did a simple search/replace operation. While here update the tests to look for the 'G' status and the manpage, which was also missing the documentation for the 'C' status in got patch. ok stsp@

since diffs are often enclosed in other formats (e.g. emails) we might parse something and think it's a blob id when it's not. This should already happens, but apply_patch is looking for the wrong error due to a leftover from previous attempts. Reported by stsp@ while here tweak the test_patch_merge_unknown_blob to also try with a dummy commit id, as now got-read-patch requires it in order to consider a blob id. ok stsp@

suggested by and ok stsp@

Parse the "blob -" metadata in diffs produced by 'got diff' and use the original file for patching. Then, use the diff3 with the current version of the file to merge the differences. This solves many failures automagically or at least turns them into a conflict. ok/improvements stsp@

Otherwise the test directory it's not left in place; ok tracey@

extend the support for git-style diffs to include the "pure rename" case, i.e. when a file is renamed without any edits. ok stsp@

add a flag to got_patch to reverse a patch before applying and the -R flag for `got patch'. ok stsp@

reminded by and 'looks fine' to stsp@

this allow to apply patches from subdirectories of the work tree root. Prodded by naddy@, ok stsp@.

Move some bits from the libexec helper to the main process so we know if the patch was generated by git or not and finally document the automatic stripping of a/ and b/ prefixes added by git-diff(1). ok stsp@

This fixes a common issue when for e.g. generating patches with $ diff -u foo.orig foo where 'got patch' failed because 'foo.orig' has an 'unexpected status'. prodded by naddy, ok stsp

check_file_status used got_worktree_status to check if the file was in an allowed state, but it's wrong since the callback is not invoked on unchanged files. While here also fix a relate bug: unlink(newpath) is in the wrong spot and ends up removing files even when it shouldn't, so move it early in the got_worktree_schedule_* error handling. Finally, update the appropriate test case. It was passing before because got_worktree_schedule_add returned GOT_ERR_FILE_STATUS, not because check_file_status failed. ok stsp@

Augment got_patch_progress_cb by providing the hunks that were applied with offset (or that failed) and the recoverable error encountered during the operation (bad status, missing file, ...) got_patch now proceeds when a file fails to be patched and exits with GOT_ERR_PATCH_FAILED if no other errors are encountered. While here, also add a test for the 'hunk applied with offset' case and shrink test_patch_dont_apply and illegal_status by taking advantage that 'got patch' doesn't stop at the first error. (And add some other cases to illegal_status too.) discussed with and ok stsp@

ok stsp@

ok stsp@

with lots of help from stsp for the manpage bits!

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.

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.