Sorry for the long delay. Much thanks to Johannes for tying up the loose
ends and making several improvements seen in this round. Note: rebased on
main (it's been 4 months since v6, and there were a few conflicts...).
== 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. It could
be used to do merges when in a bare repository (thus potentially making it
of interest to Git hosting sites, i.e. "Server side merges"), or for doing a
merge of branches that aren't checked out.
It does not handle similar functionality for cherry-picks, rebases, or
reverts; that is also of interest, but is being deferred for a future
series.
== Quick Overview ==
* Patches 1-2: preparatory cleanups
* Patches 3-4: implement basic real merges
* Patches 5-6: include informational messages ("CONFLICT" messages and
such) in output
* Patches 7-15: add ability to include ls-files -u style of info in the
output
* Patch 16: support --allow-unrelated-histories
* Patch 17: augment the manual with potential usage mistakes
== Updates Log ==
Stuff NOT included that reviewers brought up in various rounds (and which
might still be an open question):
* Very generic (mode, oid, stage, filename) printing formatting[3]
* Providing similar functionality for doing cherry-picks/rebases/reverts,
i.e. a scheme for three-way merges with a specified merge-base[4]. That's
being deferred to a future series. [3]
https://lore.kernel.org/git/CABPp-BGnOes7J_piDyBUeuLVm274w4-9G3k0vR-0it3z7TPn_w@xxxxxxxxxxxxxx/
[4]
https://lore.kernel.org/git/CABPp-BEaemkGGm0cSofP0gau7YN-y6HFoi0yJbHA8+iGjxsYSA@xxxxxxxxxxxxxx/
Updates since v6:
* Significant merge-ort changes to support machine-parseable information
about individual conflicts and the paths involved in each, rather than
just a group of free-form output messages that may change over time. This
includes 5 new patches, 2 written by Johannes (and with breaking out the
other 3 from some work-in-progress changes I had including some fixes and
improvements he added).
Updates since v5:
* Used reverse_commit_list() to reverse a commit_list without extra
allocations
* Several documentation updates
Updates since v4:
* Fixed double "is" in documentation.
* Fixed a few small items with testcases
Updates since v3:
* Dropped previous patches 5, 6, and 8 of the old series; they weren't
being used and opened a can of worms[1]
* [Patch 3] Restructured argument checking, including using an enum
* [Patch 4] Restored the extended paragraph about the deprecated form of
git-merge-tree, mentioned write-tree in plumbing commands, and a few
other small fixups to the documentation
* [Patch 4] Also provide an example of a clean merge rather than just a
conflicted one
* [Patch 6] Fix the incompatible arguments check and add some tests for it
* [Patch 6] Introduce an anonymize_hash() shell function to make tests
easier to read (less repeated sed)
* [Patch 9] Rename --exclude-modes-oids-stages to --name-only; no short
option for now
* [Patch 10] When -z passed, the tree in the first section should have a
trailing NUL rather than trailing newline [1]
https://lore.kernel.org/git/CABPp-BEKuXHELVx4=5JJTj5HVOKZ=Y-4G4BK47BCZYYRSrkFsQ@xxxxxxxxxxxxxx/
Updates since v2:
* Improved patches from Dscho for the diff_warn_rename_limit() handling
* Add a -z option for NUL-terminated conflict info lines (so that filenames
do not have to be quoted)
Updates since v1 (or v3 depending on how you count; 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
[There were also two submissions of a previous series; see
https://lore.kernel.org/git/pull.1114.v2.git.git.1641403655.gitgitgadget@xxxxxxxxx/]
[https://lore.kernel.org/git/pull.1114.v2.git.git.1641403655.gitgitgadget@xxxxxxxxx/%5D]
Updates since original submission v2 (thanks to Christian, Dscho, Ramsay,
and René for suggestions and comments):
* 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 original submission v1 (thanks to Johannes Altmanninger and
Fabian for suggestions):
* 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 (15):
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-tree: support including merge messages in output
merge-ort: provide a merge_get_conflicted_files() helper function
merge-ort: remove command-line-centric submodule message from
merge-ort
merge-tree: provide a list of which files have conflicts
merge-tree: provide easy access to `ls-files -u` style info
merge-ort: store more specific conflict information
merge-ort: optionally produce machine-readable output
merge-tree: allow `ls-files -u` style info to be NUL terminated
merge-tree: add a --allow-unrelated-histories flag
git-merge-tree.txt: add a section on potentional usage mistakes
Johannes Schindelin (2):
merge-ort: store messages in a list, not in a single strbuf
merge-ort: make `path_messages` a strmap to a string_list
Documentation/git-merge-tree.txt | 235 ++++++++++++++-
builtin/merge-tree.c | 187 +++++++++++-
diff.c | 27 +-
git.c | 2 +-
merge-ort.c | 474 ++++++++++++++++++++++---------
merge-ort.h | 32 ++-
t/t4301-merge-tree-write-tree.sh | 240 ++++++++++++++++
t/t6437-submodule-merge.sh | 2 +-
8 files changed, 1032 insertions(+), 167 deletions(-)
create mode 100755 t/t4301-merge-tree-write-tree.sh
base-commit: ab336e8f1c8009c8b1aab8deb592148e69217085
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1122%2Fnewren%2Fin-core-merge-tree-v7
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1122/newren/in-core-merge-tree-v7
Pull-Request: https://github.com/gitgitgadget/git/pull/1122
Range-diff vs v6:
1: 4a7cd5542bb = 1: 8fb51817ed4 merge-tree: rename merge_trees() to trivial_merge_trees()
2: 4780ff6784d = 2: 8e0a79fa1ad merge-tree: move logic for existing merge into new function
3: 60253745f5c = 3: baf0950bcb6 merge-tree: add option parsing and initial shell for real merge function
4: f8266d39c1b = 4: 697470e50ae merge-tree: implement real merges
5: 6629af14919 = 5: 069af1ecc30 merge-ort: split out a separate display_update_messages() function
6: 17b57efb714 = 6: 53c92a5d8d9 merge-tree: support including merge messages in output
7: 4c8f42372dd = 7: 67a728d35f0 merge-ort: provide a merge_get_conflicted_files() helper function
-: ----------- > 8: 6419487e26b merge-ort: remove command-line-centric submodule message from merge-ort
8: 7b1ee417f3d ! 9: c92b81e7366 merge-tree: provide a list of which files have conflicts
@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
+ string_list_clear(&conflicted_files, 1);
+ }
if (o->show_messages) {
- printf("\n");
+- printf("\n");
++ putchar(line_termination);
merge_display_update_messages(&opt, &result);
+ }
+ merge_finalize(&opt, &result);
@@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
/* Do the relevant type of merge */
9: f1231a8fbc8 = 10: d7360f58f16 merge-tree: provide easy access to `ls-files -u` style info
-: ----------- > 11: f523b08ab5a merge-ort: store messages in a list, not in a single strbuf
-: ----------- > 12: 6b47c0fdbd7 merge-ort: make `path_messages` a strmap to a string_list
-: ----------- > 13: 7eb70f77c81 merge-ort: store more specific conflict information
-: ----------- > 14: 662e97f2ed4 merge-ort: optionally produce machine-readable output
10: 22297e6ce75 ! 15: b314aa9c436 merge-tree: allow `ls-files -u` style info to be NUL terminated
@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
if (!result.clean) {
struct string_list conflicted_files = STRING_LIST_INIT_NODUP;
const char *last = NULL;
-@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
- string_list_clear(&conflicted_files, 1);
- }
- if (o->show_messages) {
-- printf("\n");
-+ putchar(line_termination);
- merge_display_update_messages(&opt, &result);
- }
- merge_finalize(&opt, &result);
@@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
N_("do a trivial merge only"), MODE_TRIVIAL),
OPT_BOOL(0, "messages", &o.show_messages,
@@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Check conflicted oids and
+
+ test_expect_code 1 git merge-tree --write-tree -z tweak1 side2 >out &&
+ anonymize_hash out >actual &&
++ printf "\\n" >>actual &&
+
+ # Expected results:
+ # "greeting" should merge with conflicts
@@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Check conflicted oids and
+
+ EOF
+
-+ cat <<-EOF >>expect &&
-+ Auto-merging greeting
-+ CONFLICT (content): Merge conflict in greeting
-+ CONFLICT (file/directory): directory in the way of whatever from tweak1; moving it to whatever~tweak1 instead.
-+ CONFLICT (modify/delete): whatever~tweak1 deleted in side2 and modified in tweak1. Version tweak1 of whatever~tweak1 left in tree.
-+ Auto-merging Αυτά μου φαίνονται κινέζικα
-+ CONFLICT (content): Merge conflict in Αυτά μου φαίνονται κινέζικα
++ q_to_nul <<-EOF >>expect &&
++ 1QgreetingQAuto-mergingQAuto-merging greeting
++ Q1QgreetingQCONFLICT (contents)QCONFLICT (content): Merge conflict in greeting
++ Q2Qwhatever~tweak1QwhateverQCONFLICT (file/directory)QCONFLICT (file/directory): directory in the way of whatever from tweak1; moving it to whatever~tweak1 instead.
++ Q1Qwhatever~tweak1QCONFLICT (modify/delete)QCONFLICT (modify/delete): whatever~tweak1 deleted in side2 and modified in tweak1. Version tweak1 of whatever~tweak1 left in tree.
++ Q1QΑυτά μου φαίνονται κινέζικαQAuto-mergingQAuto-merging Αυτά μου φαίνονται κινέζικα
++ Q1QΑυτά μου φαίνονται κινέζικαQCONFLICT (contents)QCONFLICT (content): Merge conflict in Αυτά μου φαίνονται κινέζικα
++ Q
+ EOF
+
+ test_cmp expect actual
11: db73c6dd823 = 16: 66df0c2e837 merge-tree: add a --allow-unrelated-histories flag
12: d58a7c7a9f6 ! 17: 70ea8281952 git-merge-tree.txt: add a section on potentional usage mistakes
@@ Documentation/git-merge-tree.txt: with linkgit:git-merge[1]:
+<<IM,Informational messages>> section has the necessary info, though it
+is not designed to be machine parseable.
+
++Do NOT assume that each paths from <<CFI,Conflicted file info>>, and
++the logical conflicts in the <<IM,Informational messages>> have a
++one-to-one mapping, nor that there is a one-to-many mapping, nor a
++many-to-one mapping. Many-to-many mappings exist, meaning that each
++path can have many logical conflict types in a single merge, and each
++logical conflict type can affect many paths.
++
+Do NOT assume all filenames listed in the <<IM,Informational messages>>
+section had conflicts. Messages can be included for files that have no
+conflicts, such as "Auto-merging <file>".
--
gitgitgadget
