add some helper functions to compute hashes This adds a set of functions to abstract over SHA1Init, SHA1Update, SHA1Final, their respective SHA256 variants and how to compare digests. Replace all the SHA1*() usage with the new APIs. It's a preparatory step for sha256 handling. ok stsp@

rename lib/sha1.c to lib/hash.c It will soon grow functions to deal with sha256 too. stsp@ agrees.

include sha2.h too where sha1.h is included 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>

use SHA1_DIGEST_LENGTH instead of sizeof(id) ok stsp

avoid copying reused deltas to delta cache file; copy from pack file instead ok op@

add missing free() of delta buffers in several error paths

change add_delta to take an off_t instead of size_t. add_delta already calls got_delta_open casting the size_t to off_t, and all the add_delta callers pass an off_t anyway; fixes an implicit off_t truncation. ok stsp@

convert got_pack' filesize to off_t; ok stsp@

check size before calling mmap(2) It's only a preparatory step, as checking whether a size_t is less than SIZE_MAX is moot. In a follow-up commit, however, the `filesize' field of the struct got_pack will become off_t and these checks will kick in. This also makes consistent how we guard mmap(2) against empty files. ok and improvements stsp@

add missing `goto done;' on error path; ok stsp@

fix off_t type mismatch off_t is a signed type and depending on the platform, it can be "long" or "long long", so cast to long long for printf().

change got_pack_parse_offset_delta tslen argument to size_t The tslen argument is always in the (1..9) range so `int' is technically fine (even int8_t would be!) but all the callers are passing a size_t, so change the type accordingly. ok stsp@

close parent's end of imsg pipe before waiting for a child process to exit Prevents a dead-lock in 'tog log' where tog wants to exit (e.g. because the user pressed Ctrl-C) while a got-read-pack child process wants to send more commits. Closing the parent's pipe descriptor makes writes to the pipe fail in the child process. The child then unwinds via an ERR_EOF error and exits, instead of forever polling its end of the pipe in order to write more data. ok jamsek

provide a more useful error if the size of a packed object won't fit in 64 bits

do not crash if no delta cache is present while parsing deltas