[PATCH v2 0/4] git add --resolved

[Junio C Hamano <gitster@pobox.com>]

When you are the maintainer of a project and make many merges day
in, day out, a lot of your time is spent resolving conflicts and
adding the results to the index.  It is not unusual to have local
changes in your working tree that are unrelated to any particular
merge [*].  In such cases, 'git add -u', which adds all changes in
the working tree to the index, does not help much.

Here is a new option for 'git add' that lets you add paths with
resolved conflicts to the index, while keeping unrelated local
changes out.

The first three patches perform preliminary refactorings.

 - [1/4] is a totally unrelated code cleanup that almost disappears
   when viewed with 'git show -w', but it was an eyesore to have so
   many lines with broken indentation while working in the vicinity.

 - [2/4] consolidates a helper function to determine whether a line
   is a conflict marker (replacing two slightly different
   definitions).

 - [3/4] introduces a helper that makes registering path removals
   from the index as easy as adding them, complete with automatic
   '--dry-run' and '--verbose' support.

The fourth patch implements the new feature.  Relative to v1, the
detection of the use of the '-A' option was fixed and the Meson build
file was updated to include the new test script, both thanks to
Michael Montalbo.  In addition, the has_conflict_markers() helper
has been tightened to bail early on a binary file.

 1/4: read-cache: reindent
 2/4: merge-ll: consolidate conflict marker scanning logic
 3/4: read-cache: add remove_file_from_index_with_flags()
 4/4: add: introduce '--resolved' option

[Footnote]

 * This is not limited to my own workflow. An earlier message on
   this topic worth mentioning is:

   https://lore.kernel.org/git/CA+55aFxP8j7YbYaRXt-8Y0n8cHafB=FPKMy8gKFYH5QsKX4S=Q@mail.gmail.com/

 Documentation/git-add.adoc |  10 +++-
 builtin/add.c              |  92 ++++++++++++++++++++++++++++---
 diff.c                     |  25 +--------
 merge-ll.c                 |  56 +++++++++++++++++++
 merge-ll.h                 |   2 +
 read-cache-ll.h            |   3 ++
 read-cache.c               |  89 +++++++++++++++++-------------
 rerere.c                   |  38 +++----------
 t/meson.build              |   1 +
 t/t2207-add-resolved.sh    | 108 +++++++++++++++++++++++++++++++++++++
 10 files changed, 323 insertions(+), 101 deletions(-)
 create mode 100755 t/t2207-add-resolved.sh

Range-diff against v1:
4:  c503fbb785 = 1:  e46fe3e887 read-cache: reindent
1:  03ea86d803 = 2:  b5490819bd merge-ll: consolidate conflict marker scanning logic
2:  e94e3c1390 = 3:  e1f4aba480 read-cache: add remove_file_from_index_with_flags()
3:  73679d6b69 ! 4:  b1308a0ca1 add: introduce '--resolved' option
    @@ builtin/add.c: int cmd_add(int argc,
     -	if (addremove && take_worktree_changes)
     -		die(_("options '%s' and '%s' cannot be used together"), "-A", "-u");
     +	die_for_incompatible_opt3(take_worktree_changes, "-u/--update",
    -+				  0 <= addremove_explicit, "-A/--all",
    ++				  0 < addremove_explicit, "-A/--all",
     +				  add_resolved, "--resolved");
      
      	if (!show_only && ignore_missing)
    @@ merge-ll.c: int is_conflict_marker_line(const char *line, unsigned long len, int
     +			has_markers = 1;
     +			break;
     +		}
    ++		if (buffer_is_binary(sb.buf,
    ++				     ULONG_MAX <= sb.len ? ULONG_MAX : sb.len))
    ++			break;
     +	}
     +	fclose(f);
     +	strbuf_release(&sb);
    @@ merge-ll.h: enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
      
      #endif
     
    + ## t/meson.build ##
    +@@ t/meson.build: integration_tests = [
    +   't2204-add-ignored.sh',
    +   't2205-add-worktree-config.sh',
    +   't2206-add-submodule-ignored.sh',
    ++  't2207-add-resolved.sh',
    +   't2300-cd-to-toplevel.sh',
    +   't2400-worktree-add.sh',
    +   't2401-worktree-prune.sh',
    +
      ## t/t2207-add-resolved.sh (new) ##
     @@
     +#!/bin/sh
-- 
2.55.0-609-g9a17695db7