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@.

change the three hardcoded seeds to fresh ones generated on demand via arc4random. Suggested/fixed by and ok stsp@

This flag can be expressed as m->reused_delta_offset != 0 because all deltas in valid pack files will be written at a non-zero offset. We allocate a huge number of these structs during packing, so every little bit helps.

With files sorted properly for deltification we produce better deltas but end up consuming more memory and risk running into OpenBSD ulimits during packing. To compensate, reduce the threshold for the amount of delta data we store in memory, spooling more deltas into the cache file. ok op@

This reduces memory use by gotadmin pack. The goal is to sort files which share a path next to each other for deltification. A hash of the path is good enough for this purpose and consumes less memory than a verbatim copy of the path. Git does something similar. ok op@

The old code was broken and stored an empty path or filenames, instead of a repository-relative path. Which means we didn't sort files for deltification as was intended. Fixing this provides much better deltas in large pack files written by gotadmin pack -a. In my test case, pack size changed from 2GB to 1.5GB. ok op@

let got_patch own fileindex_path and call got_worktree_patch_complete only if got_wokrtree_patch_prepare hasn't failed. suggested by stsp@

Instead of flushing the fileindex after every patch in the patchfile just reuse the same fileindex and sync it only at the end of the patch operation. This speeds up 'got patch' on large repositories by quite a lot.

Saves us from doing a malloc/free call for every item on the list. ok op@

ok op@

imsg_read() will call recvmsg() on the file descriptor regardless of the read buffer's state, so we should ensure that data is ready. The read buffer is used by imsg_get(), not imsg_read(). We already call imsg_get() before imsg_read(), and call the latter only if imsg_get() returns zero.

This speeds up loading of trees significantly. ok op@

Avoids some extra malloc/free in a performance-critical path. ok op@

no functional change