If we enter the sha1_position() function with "lo == hi",
we have no elements. But the do-while loop means that we'll
enter the loop body once anyway, picking "mi" at that same
value and comparing nonsense to our desired key. This is
unlikely to match in practice, but we still shouldn't be
looking at the memory in the first place.

This bug is inherited from git.git; it was fixed there in
e01580cfe01526ec2c4eb4899f776a82ade7e0e1.

patch_generate: represent buffers as void pointers

tsort: remove idempotent conditional assignment

win32: provide fast-path for retrying filesystem operations

When using the `do_with_retries` macro for retrying filesystem
operations in the posix emulation layer, allow the remediation function
to return `GIT_RETRY`, meaning that the error was believed to be
remediated, and the operation should be retried immediately, without
a sleep.

This is a slightly more general solution to the problem fixed in #4312.

Fixed an issue where the retry logic on p_unlink sleeps before it tries setting a file to write mode causing unnecessary slowdown.

The conditional `run < minrun` can never be true directly after
assigning `run = minrun`. Remove it to avoid confusion.

Configuration file fixes with includes

Patch ID calculation