From 7976721d171e17330486b403e868b594cd238295 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 18 Jun 2022 00:20:59 +0000 Subject: [PATCH] merge-tree: add a --allow-unrelated-histories flag Folks may want to merge histories that have no common ancestry; provide a flag with the same name as used by `git merge` to allow this. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- Documentation/git-merge-tree.txt | 5 +++++ builtin/merge-tree.c | 7 ++++++- t/t4301-merge-tree-write-tree.sh | 24 +++++++++++++++++++++++- 3 files changed, 34 insertions(+), 2 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 75b57f8aba..628324646d 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -59,6 +59,11 @@ OPTIONS default is to include these messages if there are merge conflicts, and to omit them otherwise. +--allow-unrelated-histories:: + merge-tree will by default error out if the two branches specified + share no common history. This flag can be given to override that + check and make the merge proceed anyway. + [[OUTPUT]] OUTPUT ------ diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index c159e31774..ae5782917b 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -399,6 +399,7 @@ enum mode { struct merge_tree_options { int mode; + int allow_unrelated_histories; int show_messages; int name_only; }; @@ -434,7 +435,7 @@ static int real_merge(struct merge_tree_options *o, * merge_incore_recursive in merge-ort.h */ merge_bases = get_merge_bases(parent1, parent2); - if (!merge_bases) + if (!merge_bases && !o->allow_unrelated_histories) die(_("refusing to merge unrelated histories")); merge_bases = reverse_commit_list(merge_bases); @@ -500,6 +501,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) &o.name_only, N_("list filenames without modes/oids/stages"), PARSE_OPT_NONEG), + OPT_BOOL_F(0, "allow-unrelated-histories", + &o.allow_unrelated_histories, + N_("allow merging unrelated histories"), + PARSE_OPT_NONEG), OPT_END() }; diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh index 88e75b18cc..f091259a55 100755 --- a/t/t4301-merge-tree-write-tree.sh +++ b/t/t4301-merge-tree-write-tree.sh @@ -44,7 +44,13 @@ test_expect_success setup ' git checkout side3 && git mv numbers sequence && test_tick && - git commit -m rename-numbers + git commit -m rename-numbers && + + git switch --orphan unrelated && + >something-else && + git add something-else && + test_tick && + git commit -m first-commit ' test_expect_success 'Clean merge' ' @@ -215,4 +221,20 @@ test_expect_success 'NUL terminated conflicted file "lines"' ' test_cmp expect actual ' +test_expect_success 'error out by default for unrelated histories' ' + test_expect_code 128 git merge-tree --write-tree side1 unrelated 2>error && + + grep "refusing to merge unrelated histories" error +' + +test_expect_success 'can override merge of unrelated histories' ' + git merge-tree --write-tree --allow-unrelated-histories side1 unrelated >tree && + TREE=$(cat tree) && + + git rev-parse side1:numbers side1:greeting side1:whatever unrelated:something-else >expect && + git rev-parse $TREE:numbers $TREE:greeting $TREE:whatever $TREE:something-else >actual && + + test_cmp expect actual +' + test_done -- 2.11.4.GIT