fix, PEBKAC, don't pass NULL to sha_fin()

as we demanded a non-NULL argument explicitly.

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, provide an analysis target utilising clang --analyze

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, compare unsigned vars with unsigned values

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene'

* code/hygiene:
  hygiene, compare unsigned vars with unsigned values
  chore, provide an analysis target utilising clang --analyze
  fix, PEBKAC, don't pass NULL to sha_fin()