-s for short. Moves log search to -S. Patch by Evan Silberman

This implementation marked commits and trees as enumerated before all trees which they depend on were enumerated. This behaviour leads to incomplete pack files when a tree is only partially packed and got-read-pack hits a missing tree entry as a result. The algorithm must be reworked such that packed leave nodes are marked enumerated first, then bubble-up. Found by op@

Fixes an error where got-read-pack errors out with "bad object data" during 'got send' because we ended up handing a tag object to the commit object parser.

pointed out by op@

ok op@

otherwise we end up with a staged empty edit for that file. ok stsp@

This approach uses more memory but is much faster. To offset the additional memory usage somewhat the cache now stores very small deltas only. However, overall memory usage goes up. Hopefully we will find a way to reduce this later. ok op@

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

Avoids clobbering open files for delta base/accumulation, leaking file descriptors, and triggering errors from close(2) during got_repo_close() as we try to close the same file descriptor more than once.

ok tracey

with a fix from + ok op@

-portable doesn't need this directly.

ok thomas

found by tracey

found by tracey

This prepares for callers of got_repo_open() that cannot afford to open files in /tmp, such as gotwebd. In a follow-up change, we could ask such callers to pass in the required amount of open temporary files. One consequence is that got_repo_open() now requires the "cpath" pledge promise. Add the "cpath" promise to affected callers and remove it once the repository has been opened. ok tracey

The 'nskip' variable is supposed to reflect commits which are waiting on the queue and have the 'skip' color. Only increment 'nskip' when adding such commits to the queue. Problem observed with got send -T and a tag pointing to a deleted branch. Test to reproduce the bug written by op@.