patch: merge backend setmode() into writelines() Copy handling will be easier to handle in a single method.

patch: stop modifying gitpatch objects gitpatch objects emitted by iterhunks() were referencing file paths unmodified from the input patch. _applydif() made them usable by modifying the gitpatch objects in-place with specified path strip level. The same modified objects were then reused by iterhunks() generator. _applydiff() now copies and update the paths which completely decouples both routines. As a side effect, the "git" event now receives only metadata about copies/renames to perform the necessary copies ahead of time. Other actions are handled in the "file" event.

patch: stop handling hunkless git blocks out of stream Patch changes are emitted by iterhunks() in two separate events: 'file' when hunks have to be applied and 'git' to describe other modifications like copies or mode changes. Note that a file which mode is changed and which content is modified by the same patch will be emitted in both events. It is more convenient to handle all file modifications in a single event. This patch "zips" git actions with regular changes so both kinds can be emitted at the same place.

patch: reindent code

patch: unify iterhunks() afile/bfile handling git afile/bfile are extracted twice, once when reading a 'diff --git', and again when reading a unified hunk. The problem is not all git blocks have unified hunks (renames just have metadata) and they were not extracted the same way. This is what this patch unifies.

patch: git metadata was ignored if strip > 1 gitpatch objects emitted by iterhunks() are modified in place by applydiff(). Processing them earlier improves iterhunks() isolation. applydiff() modifying them should still be fixed though.