Note: Depends on en/remerge-diff

(Note2: This is a continuation of my series at [0], but I can't change the
base repository for a pull request in GitHub so I had to open a new PR and
that makes it look like a new series. [0]
https://lore.kernel.org/git/pull.1114.v2.git.git.1641403655.gitgitgadget@gmail.com/)

== Basic Summary ==

This series introduces a new mode to git merge-tree allowing it to perform
real merges (three-way text content merges, recursive ancestor
consolidation, rename detection, proper directory/file conflict handling,
etc.) and write the result as a toplevel tree. It doesn't touch the working
tree or index, and doesn't create any commits or update any refs.

== Updates Log ==

Stuff NOT included that reviewers brought up in the last round:

 * Very generic (mode, oid, stage, filename) printing formatting[1]
 * Always printing 3 stages for each filename with conflicts[2] [1]
   https://lore.kernel.org/git/CABPp-BGnOes7J_piDyBUeuLVm274w4-9G3k0vR-0it3z7TPn_w@mail.gmail.com/
   [2]
   https://lore.kernel.org/git/CABPp-BG2rMEYBLuBW=0wtpJe4aUFGCFa8D0NTSKz9Sm+CkXPxw@mail.gmail.com/

Updates since v3 (which looks like v1 due to the re-submit; thanks to René,
Ævar, Christian, Dscho for very helpful feedback):

 * New patch from Dscho allowing diff_warn_rename_limit() to print somewhere
   other than stdout (I hope he's okay with me including his Signed-off-by)
 * Now prints filenames relative to prefix, much like ls-files
 * Renamed --exclude-oids-and-modes to --exclude-modes-oids-stages and gave
   it a -l shorthand; I'm wondering if I should just drop this option,
   though.
 * And numerous cleanups, in lots of areas:
   * Multiple parse-options cleanups
   * Lots of commit message cleanups
   * Wording tweaks to the "Description" section of the manual
   * Several small code cleanups
 * I dropped the RFC label

Updates since v2 (thanks to Christian, Dscho, Ramsay, and René for
suggestions and comments on v2):

 * Significant changes to output format:
   * Flags no longer take a filename for additional output; they write to
     stdout instead.
   * More information included by default when there are conflicts (no need
     to request it with additional flags, instead flags can be used to
     suppress it).
   * Provide (mode, oid, stage, file) tuples -- i.e. ls-files -u style of
     information -- when there are conflicts. Add a flag to only list
     conflicted files if that's preferred.
 * Much more thorough manual for git-merge-tree.txt
 * Renamed option from --real to --write-tree
 * Accept an optional --trivial-merge option to get old style merge-tree
   behavior
 * Allow both --write-tree and --trivial-merge to be omitted since we can
   deduce which from number of arguments
 * Document exit code when the merge cannot be run (so we can distinguish
   other error cases from conflicts)
 * testcase cleanups: test_tick, early skip of test when using recursive
   backend, variable renames, etc.
 * various minor code cleanups
 * Add a new --allow-unrelated-histories option (with same meaning as the
   one used in git merge)
 * Rebased on top of en/remerge-diff to avoid a small conflict

Updates since v1 (thanks to Johannes Altmanninger and Fabian for suggestions
on v1):

 * Fixed a bad patch splitting, and a style issue pointed out by Johannes
   Altimanninger
 * Fixed misleading commit messages in new test cases
 * Fixed my comments about how commit-tree could be used to correctly use
   two -p flags

Elijah Newren (12):
  merge-tree: rename merge_trees() to trivial_merge_trees()
  merge-tree: move logic for existing merge into new function
  merge-tree: add option parsing and initial shell for real merge
    function
  merge-tree: implement real merges
  merge-ort: split out a separate display_update_messages() function
  merge-ort: allow update messages to be written to different file
    stream
  merge-tree: support including merge messages in output
  merge-ort: provide a merge_get_conflicted_files() helper function
  merge-tree: provide a list of which files have conflicts
  merge-tree: provide easy access to `ls-files -u` style info
  merge-tree: add a --allow-unrelated-histories flag
  git-merge-tree.txt: add a section on potentional usage mistakes

Johannes Schindelin (1):
  diff: allow diff_warn_rename_limit to write somewhere besides stdout

 Documentation/git-merge-tree.txt | 179 ++++++++++++++++++++++++++++---
 builtin/merge-tree.c             | 162 +++++++++++++++++++++++++---
 diff.c                           |  20 ++--
 diff.h                           |   3 +-
 git.c                            |   2 +-
 merge-ort.c                      | 109 ++++++++++++-------
 merge-ort.h                      |  30 ++++++
 merge-recursive.c                |   3 +-
 t/t4301-merge-tree-write-tree.sh | 164 ++++++++++++++++++++++++++++
 9 files changed, 603 insertions(+), 69 deletions(-)
 create mode 100755 t/t4301-merge-tree-write-tree.sh

base-commit: ea5df61cf358d3c831189e2f04863abc2157e3e1

Submitted-As: https://lore.kernel.org/git/pull.1122.v2.git.1643479633.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1122.git.1642888562.gitgitgadget@gmail.com