[PATCH 0/5] use size_t for xdiff mmfile_t

An earlier series tried to simplify ll_ext_merge()'s code to read back the merge result from a temporary file, but Elijah pointed out some subtle integer overflow confusion:

  https://lore.kernel.org/git/CABPp-BG9Hkc7i_JxAbYfyzu+b4Mc_pZUr0jJF=vY0jHSARpHzw@mail.gmail.com/

I dug a little bit and found that similar problems exist elsewhere. So here's an attempt to make things at least incrementally better. And patch 4 is the original cleanup I set out to do. ;)

There are a few textual conflicts with the v3 of jk/merge-ll-tempfile-cleanup that I just sent out. They should be easy-ish to resolve, but I'm happy to just base this on that topic if it's easier.

  [1/5]: xdiff: clean up read_mmfile() allocations on error
  [2/5]: xdiff: replace mmbuffer_t with mmfile_t
  [3/5]: xdiff: use size_t for buffer sizes
  [4/5]: merge-ll: use read_mmfile() to read external merge results
  [5/5]: xdiff: NUL-terminate buffers read by read_mmfile()

 Documentation/technical/api-merge.adoc |  7 +++---
 apply.c                                |  2 +-
 builtin/checkout.c                     |  2 +-
 builtin/merge-file.c                   |  2 +-
 builtin/merge-tree.c                   |  2 +-
 builtin/rerere.c                       |  8 +++++--
 diff.c                                 |  2 +-
 merge-blobs.c                          |  2 +-
 merge-ll.c                             | 33 +++++++++-----------------
 merge-ll.h                             |  4 ++--
 merge-ort.c                            |  4 ++--
 notes-merge.c                          |  2 +-
 rerere.c                               | 11 ++++-----
 xdiff-interface.c                      |  5 ++--
 xdiff/xdiff.h                          | 11 +++------
 xdiff/xmerge.c                         |  4 ++--
 xdiff/xutils.c                         |  4 ++--
 17 files changed, 46 insertions(+), 59 deletions(-)

-Peff