add tests for rebasing merged history

Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 258 insertions, 0 deletions

diff --git a/t/t3425-rebase-topology-merges.sh b/t/t3425-rebase-topology-merges.sh
new file mode 100755
index 0000000000..5400a059e4
--- /dev/null
+++ b/t/t3425-rebase-topology-merges.sh
@@ -0,0 +1,258 @@
+#!/bin/sh
+
+test_description='rebase topology tests with merges'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+test_revision_subjects () {
+	expected="$1"
+	shift
+	set -- $(git log --format=%s --no-walk=unsorted "$@")
+	test "$expected" = "$*"
+}
+
+# a---b-----------c
+#      \           \
+#       d-------e   \
+#        \       \   \
+#         n---o---w---v
+#              \
+#               z
+test_expect_success 'setup of non-linear-history' '
+	test_commit a &&
+	test_commit b &&
+	test_commit c &&
+	git checkout b &&
+	test_commit d &&
+	test_commit e
+
+	git checkout c &&
+	test_commit g &&
+	revert h g &&
+	git checkout d &&
+	cherry_pick G g &&
+	test_commit i &&
+	git checkout b &&
+	test_commit f
+
+	git checkout d &&
+	test_commit n &&
+	test_commit o &&
+	test_merge w e &&
+	test_merge v c &&
+	git checkout o &&
+	test_commit z
+'
+
+test_run_rebase () {
+	result=$1
+	shift
+	test_expect_$result "rebase $* after merge from upstream" "
+		reset_rebase &&
+		git rebase $* e w &&
+		test_cmp_rev e HEAD~2 &&
+		test_linear_range 'n o' e..
+	"
+}
+test_run_rebase success ''
+test_run_rebase success -m
+test_run_rebase success -i
+
+test_run_rebase () {
+	result=$1
+	shift
+	expected=$1
+	shift
+	test_expect_$result "rebase $* of non-linear history is linearized in place" "
+		reset_rebase &&
+		git rebase $* d w &&
+		test_cmp_rev d HEAD~3 &&
+		test_linear_range "\'"$expected"\'" d..
+	"
+}
+#TODO: make order consistent across all flavors of rebase
+test_run_rebase success 'e n o' ''
+test_run_rebase success 'e n o' -m
+test_run_rebase success 'n o e' -i
+
+test_run_rebase () {
+	result=$1
+	shift
+	expected=$1
+	shift
+	test_expect_$result "rebase $* of non-linear history is linearized upstream" "
+		reset_rebase &&
+		git rebase $* c w &&
+		test_cmp_rev c HEAD~4 &&
+		test_linear_range "\'"$expected"\'" c..
+	"
+}
+#TODO: make order consistent across all flavors of rebase
+test_run_rebase success 'd e n o' ''
+test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' -i
+
+test_run_rebase () {
+	result=$1
+	shift
+	expected=$1
+	shift
+	test_expect_$result "rebase $* of non-linear history with merges after upstream merge is linearized" "
+		reset_rebase &&
+		git rebase $* c v &&
+		test_cmp_rev c HEAD~4 &&
+		test_linear_range "\'"$expected"\'" c..
+	"
+}
+#TODO: make order consistent across all flavors of rebase
+test_run_rebase success 'd e n o' ''
+test_run_rebase success 'd e n o' -m
+test_run_rebase success 'd n o e' -i
+
+test_expect_success "rebase -p is no-op in non-linear history" "
+	reset_rebase &&
+	git rebase -p d w &&
+	test_cmp_rev w HEAD
+"
+
+test_expect_success "rebase -p is no-op when base inside second parent" "
+	reset_rebase &&
+	git rebase -p e w &&
+	test_cmp_rev w HEAD
+"
+
+test_expect_failure "rebase -p --root on non-linear history is a no-op" "
+	reset_rebase &&
+	git rebase -p --root w &&
+	test_cmp_rev w HEAD
+"
+
+test_expect_success "rebase -p re-creates merge from side branch" "
+	reset_rebase &&
+	git rebase -p z w &&
+	test_cmp_rev z HEAD^ &&
+	test_cmp_rev w^2 HEAD^2
+"
+
+test_expect_success "rebase -p re-creates internal merge" "
+	reset_rebase &&
+	git rebase -p c w &&
+	test_cmp_rev c HEAD~4 &&
+	test_cmp_rev HEAD^2^ HEAD~3 &&
+	test_revision_subjects 'd n e o w' HEAD~3 HEAD~2 HEAD^2 HEAD^ HEAD
+"
+
+test_expect_success "rebase -p can re-create two branches on onto" "
+	reset_rebase &&
+	git rebase -p --onto c d w &&
+	test_cmp_rev c HEAD~3 &&
+	test_cmp_rev c HEAD^2^ &&
+	test_revision_subjects 'n e o w' HEAD~2 HEAD^2 HEAD^ HEAD
+"
+
+#       f
+#      /
+# a---b---c---g---h
+#      \
+#       d---G---i
+#        \       \
+#         e-------u
+#
+# uppercase = cherry-picked
+# h = reverted g
+test_expect_success 'setup of non-linear-history for patch-equivalence tests' '
+	git checkout e &&
+	test_merge u i
+'
+
+test_expect_success "rebase -p re-creates history around dropped commit matching upstream" "
+	reset_rebase &&
+	git rebase -p h u &&
+	test_cmp_rev h HEAD~3 &&
+	test_cmp_rev HEAD^2^ HEAD~2 &&
+	test_revision_subjects 'd i e u' HEAD~2 HEAD^2 HEAD^ HEAD
+"
+
+test_expect_success "rebase -p --onto in merged history drops patches in upstream" "
+	reset_rebase &&
+	git rebase -p --onto f h u &&
+	test_cmp_rev f HEAD~3 &&
+	test_cmp_rev HEAD^2^ HEAD~2 &&
+	test_revision_subjects 'd i e u' HEAD~2 HEAD^2 HEAD^ HEAD
+"
+
+test_expect_success "rebase -p --onto in merged history does not drop patches in onto" "
+	reset_rebase &&
+	git rebase -p --onto h f u &&
+	test_cmp_rev h HEAD~3 &&
+	test_cmp_rev HEAD^2~2 HEAD~2 &&
+	test_revision_subjects 'd G i e u' HEAD~2 HEAD^2^ HEAD^2 HEAD^ HEAD
+"
+
+# a---b---c---g---h
+#      \
+#       d---G---s
+#        \   \ /
+#         \   X
+#          \ / \
+#           e---t
+#
+# uppercase = cherry-picked
+# h = reverted g
+test_expect_success 'setup of non-linear-history for dropping whole side' '
+	git checkout G &&
+	test_merge s e &&
+	git checkout e &&
+	test_merge t G
+'
+
+test_expect_failure "rebase -p drops merge commit when entire first-parent side is dropped" "
+	reset_rebase &&
+	git rebase -p h s &&
+	test_cmp_rev h HEAD~2 &&
+	test_linear_range 'd e' h..
+"
+
+test_expect_success "rebase -p drops merge commit when entire second-parent side is dropped" "
+	reset_rebase &&
+	git rebase -p h t &&
+	test_cmp_rev h HEAD~2 &&
+	test_linear_range 'd e' h..
+"
+
+# a---b---c
+#      \
+#       d---e
+#        \   \
+#         n---r
+#          \
+#           o
+#
+# r = tree-same with n
+test_expect_success 'setup of non-linear-history for empty commits' '
+	git checkout n &&
+	git merge --no-commit e &&
+	git reset n . &&
+	git commit -m r &&
+	git reset --hard &&
+	git clean -f &&
+	git tag r
+'
+
+test_expect_success "rebase -p re-creates empty internal merge commit" "
+	reset_rebase &&
+	git rebase -p c r &&
+	test_cmp_rev c HEAD~3 &&
+	test_cmp_rev HEAD^2^ HEAD~2 &&
+	test_revision_subjects 'd e n r' HEAD~2 HEAD^2 HEAD^ HEAD
+"
+
+test_expect_success "rebase -p re-creates empty merge commit" "
+	reset_rebase &&
+	git rebase -p o r &&
+	test_cmp_rev e HEAD^2 &&
+	test_cmp_rev o HEAD^ &&
+	test_revision_subjects 'r' HEAD
+"
+
+test_done