[PATCH v7 0/4] branch: let --delete-merged find squash merged branches

["Harald Nordgren via GitGitGadget" <gitgitgadget@gmail.com>]

Branches merged on GitHub with "Squash and merge" or "Rebase and merge" are
never deleted by git branch --delete-merged, because their tips are not
reachable from the upstream. This treats such a branch as merged when some
upstream commit contains all of its changes, and names that commit in the
output:

Deleted branch topic (was 1a2b3c4, landed as 9f8e7d6).


Changes in v7:

 * Added a test that --delete-integrated keeps a branch whose changes did
   not land.
 * Read the index once before the walk in find_landed_commits(), instead of
   for every file merge at every candidate commit.
 * The commit message now says the merge uses this repository's attributes
   from the working tree and the index.

Changes in v6:

 * Read the index before the file merge, so .gitattributes that are only in
   the index are honored too.
 * Renamed the diff_options variables from opt to diffopt.

Changes in v5:

 * git branch -h lists --delete-integrated in the usage lines
 * Giving both --delete-merged and --delete-integrated dies with a short
   "cannot be used together" message instead of the full usage text

Changes in v4:

 * --delete-merged works as it does on master again: it only deletes
   branches whose tip is reachable from their upstream
 * New --delete-integrated <pattern> also deletes branches that were rebase
   or squash merged, including those squashed after upstream changed the
   same files. It replaces --squashed
 * New prep commit lets delete_branches() take a map of where each branch
   landed, so "landed as" is printed there
 * Added Junio's test that --delete-merged keeps a branch when an unrelated
   upstream commit adds an identical file
 * --dry-run works with either option, and the two options can't be combined

Changes in v3:

 * Split into multiple commits, one for rebase merges and one for squash
   merges.
 * By default a branch counts as merged when an upstream commit has its
   exact version of every file it changed. This never reads file contents,
   so it stays cheap in a partial clone. It finds rebase merges, and squash
   merges where upstream left those files alone.
 * Replace --no-squashed with an opt-in --squashed, which also finds
   branches merged after upstream changed the same files by merging those
   files.
 * Add a test for a rebase merge, and check that a squash onto changed files
   is kept without --squashed and deleted with it.

Changes in v2:

 * Diff each upstream commit once and share the result between all branches,
   faster than v1.
 * Fix a branch merged with a merge commit being reported as "landed as" the
   merge when another branch was searched first, and add a test for it. Show
   the topic commit itself in "landed as" for work that arrived through a
   merge.
 * Use git merge --squash as the example in the commit message and mention
   GitHub's squash and rebase buttons.
 * Add --no-squashed to skip the squash search.

Harald Nordgren (4):
  branch: move the deleteMerged opt-out check into a helper
  branch: let delete_branches() name where a branch landed
  branch: add --delete-integrated to delete rebase and squash merged
    branches
  branch: let --delete-integrated find branches merged onto changed
    files

 Documentation/config/branch.adoc |   8 +-
 Documentation/git-branch.adoc    |  22 +-
 builtin/branch.c                 | 361 +++++++++++++++++++++++++++++--
 t/t3200-branch.sh                | 271 +++++++++++++++++++++++
 4 files changed, 632 insertions(+), 30 deletions(-)


base-commit: 7fb6055e678f800320d8ab8cd8f201d9493d1ba0
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2425%2FHaraldNordgren%2Fbranch-delete-squashed-v7
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2425/HaraldNordgren/branch-delete-squashed-v7
Pull-Request: https://github.com/git/git/pull/2425

Range-diff vs v6:

 1:  e728b4ed0d = 1:  25d2441ce7 branch: move the deleteMerged opt-out check into a helper
 2:  9858c8c81e = 2:  18c3edb6e3 branch: let delete_branches() name where a branch landed
 3:  92bd9afda4 = 3:  7bc634c794 branch: add --delete-integrated to delete rebase and squash merged branches
 4:  006a57d7d1 ! 4:  4b5485584e branch: let --delete-integrated find branches merged onto changed files
     @@ Commit message
          unchanged. This has to read the files, so in a partial clone it may
          download blobs.
      
     +    The merge uses the attributes of this repository, from the working tree
     +    and the index, the same as a merge run here would. A merge driver that
     +    only the upstream repository has is not seen. In a bare repository only
     +    info/attributes and the global file apply.
     +
          Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
      
       ## Documentation/git-branch.adoc ##
     @@ builtin/branch.c: static void collect_branch_changes(struct landing_search *sear
      +	mmfile_t result = { 0 };
      +	int ret;
      +
     -+	repo_read_index(the_repository);
      +	read_mmblob(&base, the_repository->objects, &change->base_oid);
      +	read_mmblob(&upstream, the_repository->objects, &change->upstream_oid);
      +	read_mmblob(&branch, the_repository->objects, &change->branch_oid);
     @@ builtin/branch.c: static void collect_branch_changes(struct landing_search *sear
       	return 1;
       }
       
     +@@ builtin/branch.c: static void find_landed_commits(struct landing_search *searches,
     + 	diffopt.no_free = 1;
     + 	diff_setup_done(&diffopt);
     + 	init_changed_paths(&cache);
     ++	repo_read_index(the_repository);
     + 
     + 	for (size_t i = 0; i < searches_nr; i++) {
     + 		struct commit *landed;
      
       ## t/t3200-branch.sh ##
      @@ t/t3200-branch.sh: test_expect_success '--delete-integrated deletes a squash merged branch that was
     @@ t/t3200-branch.sh: test_expect_success '--delete-integrated deletes a squash mer
      +		EOF
      +	)
      +'
     ++
     ++test_expect_success '--delete-integrated keeps branches whose changes did not land' '
     ++	(
     ++		cd upstream &&
     ++		git checkout next &&
     ++		test_write_lines 1 2 3 4 5 6 7 8 9 10 >doc &&
     ++		git add doc &&
     ++		git commit -m "add doc" &&
     ++		git checkout main
     ++	) &&
     ++	setup_repo_for_delete_merged &&
     ++	(
     ++		cd repo &&
     ++		git checkout -b unmerged --track origin/next &&
     ++		test_write_lines 1 2 3 4 5 6 7 eight 9 10 >doc &&
     ++		git commit -a -m "edit line 8" &&
     ++		git push origin unmerged &&
     ++		git checkout -b half-landed --track origin/next &&
     ++		test_write_lines one 2 3 4 5 6 7 8 9 ten >doc &&
     ++		git commit -a -m "edit lines 1 and 10" &&
     ++		git push origin half-landed &&
     ++		git checkout -b conflicting --track origin/next &&
     ++		test_write_lines 1 2 three 4 5 6 7 8 9 10 >doc &&
     ++		git commit -a -m "edit line 3" &&
     ++		git push origin conflicting &&
     ++		git checkout --detach
     ++	) &&
     ++	(
     ++		cd upstream &&
     ++		git checkout next &&
     ++		test_write_lines 1 2 3 4 five 6 7 8 9 10 >doc &&
     ++		git commit -a -m "edit line 5" &&
     ++		test_write_lines one 2 3 4 five 6 7 8 9 10 >doc &&
     ++		git commit -a -m "take line 1 from half-landed" &&
     ++		test_write_lines one 2 THREE 4 five 6 7 8 9 10 >doc &&
     ++		git commit -a -m "edit line 3 differently" &&
     ++		git checkout main
     ++	) &&
     ++	(
     ++		cd repo &&
     ++		git fetch origin &&
     ++
     ++		git branch --delete-integrated origin/next >actual 2>&1 &&
     ++		test_must_be_empty actual &&
     ++
     ++		check_branches <<-\EOF
     ++		conflicting
     ++		half-landed
     ++		main
     ++		unmerged
     ++		EOF
     ++	)
     ++'
      +
       test_expect_success '--delete-integrated reports a merge plainly next to an unmerged branch' '
       	setup_repo_for_delete_merged &&

-- 
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