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).

This series finds the first upstream commit since the fork point that has
the branch's version of every file the branch changed, comparing only object
ids. With --squashed, a file that upstream also changed counts when merging
the branch's version into upstream's leaves it unchanged.

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-irrelevant <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                 | 355 +++++++++++++++++++++++++++++--
 t/t3200-branch.sh                | 217 +++++++++++++++++++
 4 files changed, 572 insertions(+), 30 deletions(-)

base-commit: 7e34d8174dcda3435d1404c9a30bef46afe6c13e

Submitted-As: https://lore.kernel.org/git/pull.2425.v4.git.git.1793003627.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.2425.git.git.1790667030497.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.2425.v2.git.git.1791711665.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.2425.v3.git.git.1792585717.gitgitgadget@gmail.com