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-rw-r--r--Documentation/git-merge.txt13
-rw-r--r--builtin/merge.c12
-rwxr-xr-xt/t3033-merge-toplevel.sh16
-rwxr-xr-xt/t3412-rebase-root.sh2
-rwxr-xr-xt/t5500-fetch-pack.sh6
-rwxr-xr-xt/t6009-rev-list-parent.sh4
-rwxr-xr-xt/t6010-merge-base.sh6
-rwxr-xr-xt/t6012-rev-list-simplify.sh2
-rwxr-xr-xt/t6026-merge-attr.sh3
-rwxr-xr-xt/t6029-merge-subtree.sh2
-rwxr-xr-xt/t6101-rev-parse-parents.sh2
-rwxr-xr-xt/t9400-git-cvsserver-server.sh3
12 files changed, 57 insertions, 14 deletions
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 07f7295..689aa4c 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -98,6 +98,19 @@ commit or stash your changes before running 'git merge'.
'git merge --abort' is equivalent to 'git reset --merge' when
`MERGE_HEAD` is present.
+--allow-unrelated-histories::
+ By default, `git merge` command refuses to merge histories
+ that do not share a common ancestor. This option can be
+ used to override this safety when merging histories of two
+ projects that started their lives independently. As that is
+ a very rare occasion, no configuration variable to enable
+ this by default exists and will not be added, and the list
+ of options at the top of this documentation does not mention
+ this option. Also `git pull` does not pass this option down
+ to `git merge` (instead, you `git fetch` first, examine what
+ you will be merging and then `git merge` locally with this
+ option).
+
<commit>...::
Commits, usually other branch heads, to merge into our branch.
Specifying more than one commit will create a merge with
diff --git a/builtin/merge.c b/builtin/merge.c
index 101ffef..e3db41b 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -64,6 +64,7 @@ static int option_renormalize;
static int verbosity;
static int allow_rerere_auto;
static int abort_current_merge;
+static int allow_unrelated_histories;
static int show_progress = -1;
static int default_to_upstream = 1;
static const char *sign_commit;
@@ -221,6 +222,8 @@ static struct option builtin_merge_options[] = {
OPT__VERBOSITY(&verbosity),
OPT_BOOL(0, "abort", &abort_current_merge,
N_("abort the current in-progress merge")),
+ OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
+ N_("allow merging unrelated histories")),
OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
@@ -1397,9 +1400,12 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
NULL, 0, UPDATE_REFS_DIE_ON_ERR);
- if (remoteheads && !common)
- ; /* No common ancestors found. We need a real merge. */
- else if (!remoteheads ||
+ if (remoteheads && !common) {
+ /* No common ancestors found. */
+ if (!allow_unrelated_histories)
+ die(_("refusing to merge unrelated histories"));
+ /* otherwise, we need a real merge. */
+ } else if (!remoteheads ||
(!remoteheads->next && !common->next &&
common->item == remoteheads->item)) {
/*
diff --git a/t/t3033-merge-toplevel.sh b/t/t3033-merge-toplevel.sh
index 46aadc4..c1379b0 100755
--- a/t/t3033-merge-toplevel.sh
+++ b/t/t3033-merge-toplevel.sh
@@ -19,6 +19,8 @@ test_expect_success setup '
test_commit three &&
git checkout right &&
test_commit four &&
+ git checkout --orphan five &&
+ test_commit five &&
git checkout master
'
@@ -133,4 +135,18 @@ test_expect_success 'merge FETCH_HEAD octopus non-fast-forward' '
test_cmp expect actual
'
+# two-project merge
+test_expect_success 'refuse two-project merge by default' '
+ t3033_reset &&
+ git reset --hard four &&
+ test_must_fail git merge five
+'
+
+test_expect_success 'two-project merge with --allow-unrelated-histories' '
+ t3033_reset &&
+ git reset --hard four &&
+ git merge --allow-unrelated-histories five &&
+ git diff --exit-code five
+'
+
test_done
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 0b52105..73a39f2 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -133,7 +133,7 @@ test_expect_success 'set up second root and merge' '
rm A B C &&
test_commit 6 D &&
git checkout other &&
- git merge third
+ git merge --allow-unrelated-histories third
'
cat > expect-third <<'EOF'
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 3a9b775..2569580 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -259,7 +259,8 @@ test_expect_success 'clone shallow object count' '
test_expect_success 'pull in shallow repo with missing merge base' '
(
cd shallow &&
- test_must_fail git pull --depth 4 .. A
+ git fetch --depth 4 .. A
+ test_must_fail git merge --allow-unrelated-histories FETCH_HEAD
)
'
@@ -279,9 +280,10 @@ test_expect_success 'clone shallow depth count' '
test_expect_success 'clone shallow object count' '
(
cd shallow &&
+ git prune &&
git count-objects -v
) > count.shallow &&
- grep "^count: 55" count.shallow
+ grep "^count: 54" count.shallow
'
test_expect_success 'fetch --no-shallow on full repo' '
diff --git a/t/t6009-rev-list-parent.sh b/t/t6009-rev-list-parent.sh
index 66cda17..20e3e25 100755
--- a/t/t6009-rev-list-parent.sh
+++ b/t/t6009-rev-list-parent.sh
@@ -47,7 +47,9 @@ test_expect_success 'setup roots, merges and octopuses' '
git checkout -b yetanotherbranch four &&
test_commit eight &&
git checkout master &&
- test_merge normalmerge newroot &&
+ test_tick &&
+ git merge --allow-unrelated-histories -m normalmerge newroot &&
+ git tag normalmerge &&
test_tick &&
git merge -m tripus sidebranch anotherbranch &&
git tag tripus &&
diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh
index 39b3238..e0c5f44 100755
--- a/t/t6010-merge-base.sh
+++ b/t/t6010-merge-base.sh
@@ -215,11 +215,13 @@ test_expect_success 'criss-cross merge-base for octopus-step' '
git reset --hard E &&
test_commit CC2 &&
test_tick &&
- git merge -s ours CC1 &&
+ # E is a root commit unrelated to MMR root on which CC1 is based
+ git merge -s ours --allow-unrelated-histories CC1 &&
test_commit CC-o &&
test_commit CCB &&
git reset --hard CC1 &&
- git merge -s ours CC2 &&
+ # E is a root commit unrelated to MMR root on which CC1 is based
+ git merge -s ours --allow-unrelated-histories CC2 &&
test_commit CCA &&
git rev-parse CC1 CC2 >expected &&
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
index b89cd6b..2a0fbb8 100755
--- a/t/t6012-rev-list-simplify.sh
+++ b/t/t6012-rev-list-simplify.sh
@@ -71,7 +71,7 @@ test_expect_success setup '
note J &&
git checkout master &&
- test_tick && git merge -m "Coolest" unrelated &&
+ test_tick && git merge --allow-unrelated-histories -m "Coolest" unrelated &&
note K &&
echo "Immaterial" >elif &&
diff --git a/t/t6026-merge-attr.sh b/t/t6026-merge-attr.sh
index 04c0509..ef0cbce 100755
--- a/t/t6026-merge-attr.sh
+++ b/t/t6026-merge-attr.sh
@@ -176,7 +176,8 @@ test_expect_success 'up-to-date merge without common ancestor' '
test_tick &&
(
cd repo1 &&
- git pull ../repo2 master
+ git fetch ../repo2 master &&
+ git merge --allow-unrelated-histories FETCH_HEAD
)
'
diff --git a/t/t6029-merge-subtree.sh b/t/t6029-merge-subtree.sh
index 73fc240..3e69245 100755
--- a/t/t6029-merge-subtree.sh
+++ b/t/t6029-merge-subtree.sh
@@ -49,7 +49,7 @@ test_expect_success 'setup' '
test_expect_success 'initial merge' '
git remote add -f gui ../git-gui &&
- git merge -s ours --no-commit gui/master &&
+ git merge -s ours --no-commit --allow-unrelated-histories gui/master &&
git read-tree --prefix=git-gui/ -u gui/master &&
git commit -m "Merge git-gui as our subdirectory" &&
git checkout -b work &&
diff --git a/t/t6101-rev-parse-parents.sh b/t/t6101-rev-parse-parents.sh
index 10b1452..1c6952d 100755
--- a/t/t6101-rev-parse-parents.sh
+++ b/t/t6101-rev-parse-parents.sh
@@ -19,7 +19,7 @@ test_expect_success 'setup' '
git checkout --orphan tmp &&
test_commit start2 &&
git checkout master &&
- git merge -m next start2 &&
+ git merge -m next --allow-unrelated-histories start2 &&
test_commit final &&
test_seq 40 |
diff --git a/t/t9400-git-cvsserver-server.sh b/t/t9400-git-cvsserver-server.sh
index 6146c3f..bc19811 100755
--- a/t/t9400-git-cvsserver-server.sh
+++ b/t/t9400-git-cvsserver-server.sh
@@ -45,7 +45,8 @@ test_expect_success 'setup' '
touch secondrootfile &&
git add secondrootfile &&
git commit -m "second root") &&
- git pull secondroot master &&
+ git fetch secondroot master &&
+ git merge --allow-unrelated-histories FETCH_HEAD &&
git clone -q --bare "$WORKDIR/.git" "$SERVERDIR" >/dev/null 2>&1 &&
GIT_DIR="$SERVERDIR" git config --bool gitcvs.enabled true &&
GIT_DIR="$SERVERDIR" git config gitcvs.logfile "$SERVERDIR/gitcvs.log" &&