tweak and ok stsp@

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@

future work with diff3 merge will need the fully patched file even in the nop mode ok stsp@

ok stsp@

ints have the advantage that their size is more likely to be the same across the various architecture supported by OpenBSD, thus introducing less possible differences. INT_MAX is still (at least) a few order of magnitudes higher than the patches we dealt with (even abnormal ones.) suggested by stsp@

previous commit looked at some pretty zeroes returned from calloc instead of the actual numbers received.