and also avoid to override `err' if fwrite fails. ok millert, stsp

found by smatch. ok stsp@

Since it appends to the given stailq, the ownership is moved and so don't initialize/reset it at the start and neither on error. The caller has to take care of the contents. (kind of) follow up to 2234939fb4. Based upon an original diff from jamsek; ok jamsek

Fixes the following error during gotadmin pack -a: gotadmin: raw object has unexpected size

ok jamsek

Move some functions from object_parse.c into hash.c. These functions either require hash.c code anyway or contain object ID implementation internals. Add a new file object_qid.c, for got_object_id_queue and got_object_qid. This new file must be linked to virtually every program.

Rather than assume all dependencies are required for all programs, split them out. This will make packaging easier, as well as splitting the code to use subprojects. Note that due to the use of config.h semantics, in most cases the got_compat.h header file is now at the top of the .c file it is included in, so that it can handle the system header inclusion properly.

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@

This is included portably.

Simply the SHA detection by not predicating on libcrypto, but instead checking individual header files.

Remove sha1.h as this is found portably across systems.

It will soon grow functions to deal with sha256 too. stsp@ agrees.

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>

ok stsp

ok op@

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@

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@