[PATCH 0/9] add strip_suffix as an alternative to ends_with

Here's a series to do for ends_with what the recent skip_prefix series
did for starts_with. Namely: drop some magic numbers and repeated string
literals, and hopefully make things more readable.

The first patch is René's patch 1/2, with the leak fix from Duy and typo
fixes in the commit message from me. The rest are new, and replace the
changes to prepare_packed_git_one done elsewhere in the thread.

  [1/9]: sha1_file: replace PATH_MAX buffer with strbuf in prepare_packed_git_one()
  [2/9]: add strip_suffix function
  [3/9]: implement ends_with via strip_suffix
  [4/9]: replace has_extension with ends_with
  [5/9]: use strip_suffix instead of ends_with in simple cases
  [6/9]: index-pack: use strip_suffix to avoid magic numbers
  [7/9]: strbuf: implement strbuf_strip_suffix
  [8/9]: verify-pack: use strbuf_strip_suffix
  [9/9]: prepare_packed_git_one: refactor duplicate-pack check

-Peff