In preparation for wide sha256 support; stsp@ agrees. Change done mechanically with find . -iname \*.[cy] -exec sam {} + X ,x/<sha1\.h>/i/\n#include <sha2.h>

and adjust the callers. discussed with and ok stsp@

We fail to release the memory for the nodes. To fix it however, we some consumer of the commit graph iterator need to be corrected: the returned pointer is safe to be used only up until the next iter_next call; save a copy it if it's needed afterwards too. ok stsp@

Make the choice of diff algorithm configurable by diff API users. The got and gotweb programs keep using Patience diffs which are prettier than Myers. But tog should be as fast as possible since it is being used interactively. If performance of Patience diff gets improved later we can consider switching tog back over to it. ok tracey jamsek

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

ok op@

Instead of internally opening and closing the same commit object over and over again, require callers to pass an open commit object in. Avoids an inherent dependency on the commit object cache for reasonable performance. ok op@

The singly-linked tail queue macros were added to OpenBSD 6.9 and are more widely available on other systems. ok stsp

ok millert, naddy

ok stsp