These patches were created while digging into the trailer code to better
understand how it works, in preparation for making the trailer.{c,h} files
as small as possible to make them available as a library for external users.
This series was originally created as part of [1], but are sent here
separately because the changes here are arguably more subjective in nature.
I think Patch 1 is the most important in this series. The others can wait,
if folks are opposed to adding them on their own merits at this point in
time.

These patches do not add or change any features. Instead, their goal is to
make the code easier to understand for new contributors (like myself), by
making various cleanups and improvements. Ultimately, my hope is that with
such cleanups, we are better positioned to make larger changes (especially
the broader libification effort, as in "Introduce Git Standard Library"
[2]).

Patch 1 was inspired by 576de3d956 (unpack_trees: start splitting internal
fields from public API, 2023-02-27) [3], and is in preparation for a
libification effort in the future around the trailer code. Independent of
libification, it still makes sense to discourage callers from peeking into
these trailer-internal fields.

Patches 2-3 aim to make some functions do a little less multitasking.

Patch 4 makes the find_patch_start function care about the "--no-divider"
option, because it that option matters for determining the start of the
"patch part" of the input.

Patch 5 is a renaming change to reduce overloaded language in the codebase.
It is inspired by 229d6ab6bf (doc: trailer: examples: avoid the word
"message" by itself, 2023-06-15) [4], which did a similar thing for the
interpret-trailers documentation.

[1]
https://lore.kernel.org/git/pull.1564.git.1691210737.gitgitgadget@gmail.com/T/#mb044012670663d8eb7a548924bbcc933bef116de
[2]
https://lore.kernel.org/git/20230627195251.1973421-1-calvinwan@google.com/
[3]
https://lore.kernel.org/git/pull.1149.git.1677143700.gitgitgadget@gmail.com/
[4]
https://lore.kernel.org/git/6b4cb31b17077181a311ca87e82464a1e2ad67dd.1686797630.git.gitgitgadget@gmail.com/

Linus Arver (5):
  trailer: separate public from internal portion of trailer_iterator
  trailer: split process_input_file into separate pieces
  trailer: split process_command_line_args into separate functions
  trailer: teach find_patch_start about --no-divider
  trailer: rename *_DEFAULT enums to *_UNSPECIFIED

 trailer.c | 113 ++++++++++++++++++++++++++++++------------------------
 trailer.h |  12 +++---
 2 files changed, 69 insertions(+), 56 deletions(-)

base-commit: 1b0a5129563ebe720330fdc8f5c6843d27641137

Submitted-As: https://lore.kernel.org/git/pull.1563.git.1691211879.gitgitgadget@gmail.com