Commit 1e0dacdb authored by John Keeping's avatar John Keeping Committed by Junio C Hamano

rebase: omit patch-identical commits with --fork-point

When the `--fork-point` argument was added to `git rebase`, we changed
the value of $upstream to be the fork point instead of the point from
which we want to rebase.  When $orig_head..$upstream is empty this does
not change the behaviour, but when there are new changes in the upstream
we are no longer checking if any of them are patch-identical with
changes in $upstream..$orig_head.

Fix this by introducing a new variable to hold the fork point and using
this to restrict the range as an extra (negative) revision argument so
that the set of desired revisions becomes (in fork-point mode):

	git rev-list --cherry-pick --right-only \
		$upstream...$orig_head ^$fork_point

This allows us to correctly handle the scenario where we have the
following topology:

	    C --- D --- E  <- dev
	  B  <- master@{1}
	o --- B' --- C* --- D*  <- master

- B' is a fixed-up version of B that is not patch-identical with B;
- C* and D* are patch-identical to C and D respectively and conflict
  textually if applied in the wrong order;
- E depends textually on D.

The correct result of `git rebase master dev` is that B is identified as
the fork-point of dev and master, so that C, D, E are the commits that
need to be replayed onto master; but C and D are patch-identical with C*
and D* and so can be dropped, so that the end result is:

	o --- B' --- C* --- D* --- E  <- dev

If the fork-point is not identified, then picking B onto a branch
containing B' results in a conflict and if the patch-identical commits
are not correctly identified then picking C onto a branch containing D
(or equivalently D*) results in a conflict.

This change allows us to handle both of these cases, where previously we
either identified the fork-point (with `--fork-point`) but not the
patch-identical commits *or* (with `--no-fork-point`) identified the
patch-identical commits but not the fact that master had been rewritten.
Reported-by: default avatarTed Felix <>
Signed-off-by: John Keeping's avatarJohn Keeping <>
Signed-off-by: default avatarJunio C Hamano <>
parent b6266dc8
......@@ -45,14 +45,16 @@ then
# itself well to recording empty patches. fortunately, cherry-pick
# makes this easy
git cherry-pick ${gpg_sign_opt:+"$gpg_sign_opt"} --allow-empty \
--right-only "$revisions"
--right-only "$revisions" \
rm -f "$GIT_DIR/rebased-patches"
git format-patch -k --stdout --full-index --cherry-pick --right-only \
--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
"$revisions" >"$GIT_DIR/rebased-patches"
"$revisions" ${restrict_revision+^$restrict_revision} \
if test 0 != $ret
......@@ -963,7 +963,7 @@ else
git rev-list $merges_option --pretty=oneline --abbrev-commit \
--abbrev=7 --reverse --left-right --topo-order \
$revisions | \
$revisions ${restrict_revision+^$restrict_revision} | \
sed -n "s/^>//p" |
while read -r shortsha1 rest
......@@ -59,6 +59,7 @@ If you prefer to skip this patch, run "git rebase --skip" instead.
To check out the original branch and stop rebasing, run "git rebase --abort".')
unset onto
unset restrict_revision
......@@ -546,7 +547,7 @@ then
if test -n "$new_upstream"
......@@ -572,7 +573,7 @@ require_clean_work_tree "rebase" "$(gettext "Please commit or stash them.")"
# and if this is not an interactive rebase.
mb=$(git merge-base "$onto" "$orig_head")
if test "$type" != interactive && test "$upstream" = "$onto" &&
test "$mb" = "$onto" &&
test "$mb" = "$onto" && test -z "$restrict_revision" &&
# linear history?
! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
......@@ -626,7 +627,7 @@ if test -n "$rebase_root"
......@@ -169,6 +169,29 @@ test_expect_success 'default to common base in @{upstream}s reflog if no upstrea
test_cmp expect actual
test_expect_success 'cherry-picked commits and fork-point work together' '
git checkout default-base &&
echo Amended >A &&
git commit -a --no-edit --amend &&
test_commit B B &&
test_commit new_B B "New B" &&
test_commit C C &&
git checkout default &&
git reset --hard default-base@{4} &&
test_commit D D &&
git cherry-pick -2 default-base^ &&
test_commit final_B B "Final B" &&
git rebase &&
echo Amended >expect &&
test_cmp A expect &&
echo "Final B" >expect &&
test_cmp B expect &&
echo C >expect &&
test_cmp C expect &&
echo D >expect &&
test_cmp D expect
test_expect_success 'rebase -q is quiet' '
git checkout -b quiet topic &&
git rebase -q master >output.out 2>&1 &&
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