[PATCH v3 0/3] line-log: integrate -L with the standard log output pipeline

["Michael Montalbo via GitGitGadget" <gitgitgadget@gmail.com>]

Since its introduction, git log -L has short-circuited from
log_tree_commit() into its own output function, bypassing log_tree_diff()
and log_tree_diff_flush(). This skips no_free save/restore,
always_show_header, diff_free() cleanup, and means that pickaxe (-S, -G,
--find-object) and --diff-filter cannot suppress commits whose pairs are all
filtered out, because show_log() runs before diffcore_std().

This series restructures the flow so that -L goes through the same
log_tree_diff() -> log_tree_diff_flush() path as normal single-parent and
merge diffs, then uses that to enable several non-patch diff formats.

Patch 1: revision: move -L setup before output_format-to-diff derivation

Preparatory reorder in setup_revisions(). The -L block sets a default
DIFF_FORMAT_PATCH when no format is requested; move it before the derivation
of revs->diff from output_format so the default is visible to that check. No
behavior change on its own.

Patch 2: line-log: integrate -L output with the standard log-tree pipeline

Rename line_log_print() to line_log_queue_pairs(), stripping it down to only
queue pre-computed filepairs. log_tree_diff_flush() handles show_log(),
diffcore_std(), and diff_flush(). This fixes pickaxe and --diff-filter
suppression, and aligns the commit/diff separator with the rest of log
output. Rejects --full-diff, which is not yet supported when filepairs are
pre-computed.

Patch 3: line-log: allow non-patch diff formats with -L

Expand the allowlist to accept --raw, --name-only, --name-status, and
--summary. These only read filepair metadata already set by the line-log
machinery. Diff stat formats (--stat, --numstat, --shortstat, --dirstat)
remain blocked because they call compute_diffstat() on full blob content and
would show whole-file statistics rather than range-scoped ones.

Changes since v2:

 * Switch "! test_grep" to "test_grep !" in tests.

Michael Montalbo (3):
  revision: move -L setup before output_format-to-diff derivation
  line-log: integrate -L output with the standard log-tree pipeline
  line-log: allow non-patch diff formats with -L

 Documentation/line-range-options.adoc         |  10 +-
 line-log.c                                    |  30 ++----
 line-log.h                                    |   2 +-
 log-tree.c                                    |  10 +-
 revision.c                                    |  24 +++--
 t/t4211-line-log.sh                           | 100 +++++++++++++++---
 t/t4211/sha1/expect.parallel-change-f-to-main |   1 -
 .../sha256/expect.parallel-change-f-to-main   |   1 -
 8 files changed, 121 insertions(+), 57 deletions(-)


base-commit: 9f223ef1c026d91c7ac68cc0211bde255dda6199
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2094%2Fmmontalbo%2Fmm%2Fline-log-use-log-tree-diff-flush-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2094/mmontalbo/mm/line-log-use-log-tree-diff-flush-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/2094

Range-diff vs v2:

 1:  9633eb62c6 = 1:  9633eb62c6 revision: move -L setup before output_format-to-diff derivation
 2:  7acfc5376e = 2:  7acfc5376e line-log: integrate -L output with the standard log-tree pipeline
 3:  10a3d8dde2 ! 3:  ae0b7f3ca8 line-log: allow non-patch diff formats with -L
     @@ t/t4211-line-log.sh: test_expect_success '-p shows the default patch output' '
      +test_expect_success '--raw shows mode, oid, status and path' '
      +	git log -L1,24:b.c --raw --format= >actual &&
      +	test_grep "^:100644 100644 [0-9a-f]\{7\} [0-9a-f]\{7\} M	b.c$" actual &&
     -+	! test_grep "^diff --git" actual &&
     -+	! test_grep "^@@" actual
     ++	test_grep ! "^diff --git" actual &&
     ++	test_grep ! "^@@" actual
      +'
      +
      +test_expect_success '--name-only shows path' '
      +	git log -L1,24:b.c --name-only --format= >actual &&
      +	test_grep "^b.c$" actual &&
     -+	! test_grep "^diff --git" actual &&
     -+	! test_grep "^@@" actual
     ++	test_grep ! "^diff --git" actual &&
     ++	test_grep ! "^@@" actual
      +'
      +
      +test_expect_success '--name-status shows status and path' '
      +	git log -L1,24:b.c --name-status --format= >actual &&
      +	test_grep "^M	b.c$" actual &&
     -+	! test_grep "^diff --git" actual &&
     -+	! test_grep "^@@" actual
     ++	test_grep ! "^diff --git" actual &&
     ++	test_grep ! "^@@" actual
      +'
      +
      +test_expect_success '--stat is not yet supported with -L' '

-- 
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