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[PATCHv3 1/2] add basic tests for merge-tree

Subject: [PATCHv3 1/2] add basic tests for merge-tree

## tl;dr

4 messages between Jul 14, 2010 and Jul 14, 2010.

replies: 3people: 2as markdown or json

Will Palmer· Jul 14, 2010, 17:04 UTC · lore

[PATCHv3 0/2] merge-tree: fix (merge-base a b) b a

This series notes, then fixes, a regression introduced by
15b4f7a68d8c3c8ee28424415b203f61202d65d1 /
	merge-tree: use ll_merge() not xdl_merge()
I don't know the proper terminology to describe what's being fixed here.
This seems to most-easily be triggered by (for example):
	git merge-tree $(git merge-base HEAD @{u}) HEAD @{u}
In the git repository at the moment, this could be triggered with:
	git merge-tree $(git merge-base origin/next origin/master) \
		origin/next origin/master
Though as I write this, next has only just been merged with master, so
that is not the case. For an example which is less likely to go away,
try:
	git merge-tree c9eaaab4165d8f402930d12899ec097495b599e6 \
		be16ac8cc8ce693c6adf37b80db65d10a41b4eb9 \
		9918285fb10d81af9021dae99c5f4de88ded497c

It's actually very trivial to reproduce this, to the point where I can't help but wonder how much merge-tree is actually being used. As I narrowed the test-case more and more, I was surprised by how little it took to trigger it. The first patch in this series includes some very basic tests for merge-tree, the last of which demonstrates the regression.

The second patch implements the trivial fix for it.

This is the third version of the patch. The first version of the patch included very trivial tests for merge-tree, which were really only intended to demonstrate the breakage being fixed. The second version of the patch included proper tests, with real "expected vs actual" testing, rather than dumb "did it return successfully?" checks. This version of the patch escapes the HERE documents, since they didn't require any expansions; joins up the remaining commands in && groups; and fixes a couple of lines which went beyond column 80.

Will Palmer (2):
  add basic tests for merge-tree
  fix merge-tree where two branches share no changes
 builtin/merge-tree.c  |    3 +-
 t/t4300-merge-tree.sh |  257 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 259 insertions(+), 1 deletions(-)
 create mode 100755 t/t4300-merge-tree.sh
-- 
1.7.1.703.g42c01
Will Palmer· Jul 14, 2010, 17:04 UTC · re: Will Palmer · lore

merge-tree had no test cases, so here we add some very basic tests for it, including some known-breakages.

Signed-off-by: Will Palmer <wmpalmer@gmail.com>
---
 t/t4300-merge-tree.sh |  257 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 257 insertions(+), 0 deletions(-)
 create mode 100755 t/t4300-merge-tree.sh
diff --git a/t/t4300-merge-tree.sh b/t/t4300-merge-tree.sh
new file mode 100755
index 0000000..c02c986
--- /dev/null
+++ b/t/t4300-merge-tree.sh
@@ -0,0 +1,257 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Will Palmer
+#
+
+test_description='git merge-tree'
+. ./test-lib.sh
+
+test_expect_success setup '
+	test_commit "initial" "initial-file" "initial"
+'
+
+test_expect_'file add A, !B' '
+	cat >expected <<\EXPECTED
+added in remote
+  their  100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+@@ -0,0 +1 @@
++AAA
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "add-a-not-b" "ONE" "AAA" &&
+	git merge-tree initial initial add-a-not-b >actual &&
+	test_cmp expected actual
+'
+
+test_expect_failure 'file add !A, B' '
+	cat >expected <<\EXPECTED
+added in local
+  our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "add-not-a-b" "ONE" "AAA" &&
+	git merge-tree initial add-not-a-b initial >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file add A, B (same)' '
+	cat >expected <<\EXPECTED
+added in both
+  our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  their  100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "add-a-b-same-A" "ONE" "AAA" &&
+	git reset --hard initial &&
+	test_commit "add-a-b-same-B" "ONE" "AAA" &&
+	git merge-tree initial add-a-b-same-A add-a-b-same-B >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file add A, B (different)' '
+	cat >expected <<\EXPECTED
+added in both
+  our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  their  100644 ba629238ca89489f2b350e196ca445e09d8bb834 ONE
+@@ -1 +1,5 @@
++<<<<<<< .our
+ AAA
++=======
++BBB
++>>>>>>> .their
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "add-a-b-diff-A" "ONE" "AAA" &&
+	git reset --hard initial &&
+	test_commit "add-a-b-diff-B" "ONE" "BBB" &&
+	git merge-tree initial add-a-b-diff-A add-a-b-diff-B >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file change A, !B' '
+	cat >expected <<\EXPECTED
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-a-not-b" "initial-file" "BBB" &&
+	git merge-tree initial change-a-not-b initial >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file change !A, B' '
+	cat >expected <<\EXPECTED
+merged
+  result 100644 ba629238ca89489f2b350e196ca445e09d8bb834 initial-file
+  our    100644 e79c5e8f964493290a409888d5413a737e8e5dd5 initial-file
+@@ -1 +1 @@
+-initial
++BBB
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-not-a-b" "initial-file" "BBB" &&
+	git merge-tree initial initial change-not-a-b >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file change A, B (same)' '
+	cat >expected <<\EXPECTED
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-a-b-same-A" "initial-file" "AAA" &&
+	git reset --hard initial &&
+	test_commit "change-a-b-same-B" "initial-file" "AAA" &&
+	git merge-tree initial change-a-b-same-A change-a-b-same-B >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file change A, B (different)' '
+	cat >expected <<\EXPECTED
+changed in both
+  base   100644 e79c5e8f964493290a409888d5413a737e8e5dd5 initial-file
+  our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d initial-file
+  their  100644 ba629238ca89489f2b350e196ca445e09d8bb834 initial-file
+@@ -1 +1,5 @@
++<<<<<<< .our
+ AAA
++=======
++BBB
++>>>>>>> .their
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-a-b-diff-A" "initial-file" "AAA" &&
+	git reset --hard initial &&
+	test_commit "change-a-b-diff-B" "initial-file" "BBB" &&
+	git merge-tree initial change-a-b-diff-A change-a-b-diff-B >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file change A, B (mixed)' '
+	cat >expected <<\EXPECTED
+changed in both
+  base   100644 f4f1f998c7776568c4ff38f516d77fef9399b5a7 ONE
+  our    100644 af14c2c3475337c73759d561ef70b59e5c731176 ONE
+  their  100644 372d761493f524d44d59bd24700c3bdf914c973c ONE
+@@ -7,7 +7,11 @@
+ AAA
+ AAA
+ AAA
++<<<<<<< .our
+ BBB
++=======
++CCC
++>>>>>>> .their
+ AAA
+ AAA
+ AAA
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-a-b-mix-base" "ONE" "
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA
+AAA" &&
+	test_commit "change-a-b-mix-A" "ONE" \
+		"$(sed -e "1{s/AAA/BBB/;}" -e "10{s/AAA/BBB/;}" <ONE)" &&
+	git reset --hard change-a-b-mix-base &&
+	test_commit "change-a-b-mix-B" "ONE" \
+		"$(sed -e "1{s/AAA/BBB/;}" -e "10{s/AAA/CCC/;}" <ONE)" &&
+	git merge-tree change-a-b-mix-base change-a-b-mix-A change-a-b-mix-B \
+		>actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file remove A, !B' '
+	cat >expected <<\EXPECTED
+removed in local
+  base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  their  100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "rm-a-not-b-base" "ONE" "AAA" &&
+	git rm ONE &&
+	git commit -m "rm-a-not-b" &&
+	git tag "rm-a-not-b" &&
+	git merge-tree rm-a-not-b-base rm-a-not-b rm-a-not-b-base >actual &&
+	test_cmp expected actual
+'
+
+test_expect_failure 'file remove !A, B' '
+	cat >expected <<\EXPECTED
+removed in remote
+  base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+@@ -1 +0,0 @@
+-AAA
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "rm-not-a-b-base" "ONE" "AAA" &&
+	git rm ONE &&
+	git commit -m "rm-not-a-b" &&
+	git tag "rm-not-a-b" &&
+	git merge-tree rm-a-not-b-base rm-a-not-b-base rm-a-not-b >actual &&
+	test_cmp expected actual
+'
+
+test_expect_failure 'file change A, remove B' '
+	cat >expected <<\EXPECTED
+removed in remote
+  base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  our    100644 ba629238ca89489f2b350e196ca445e09d8bb834 ONE
+@@ -1 +0,0 @@
+-BBB
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "change-a-rm-b-base" "ONE" "AAA" &&
+	test_commit "change-a-rm-b-A" "ONE" "BBB" &&
+	git reset --hard change-a-rm-b-base &&
+	git rm ONE &&
+	git commit -m "change-a-rm-b-B" &&
+	git tag "change-a-rm-b-B" &&
+	git merge-tree change-a-rm-b-base change-a-rm-b-A change-a-rm-b-B \
+		>actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'file remove A, change B' '
+	cat >expected <<\EXPECTED
+removed in local
+  base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
+  their  100644 ba629238ca89489f2b350e196ca445e09d8bb834 ONE
+EXPECTED
+
+	git reset --hard initial &&
+	test_commit "rm-a-change-b-base" "ONE" "AAA" &&
+
+	git rm ONE &&
+	git commit -m "rm-a-change-b-A" &&
+	git tag "rm-a-change-b-A" &&
+	git reset --hard rm-a-change-b-base &&
+	test_commit "rm-a-change-b-B" "ONE" "BBB" &&
+	git merge-tree rm-a-change-b-base rm-a-change-b-A rm-a-change-b-B \
+		>actual &&
+	test_cmp expected actual
+'
+
+test_done

-- 
1.7.1.703.g42c01
Junio C Hamano· Jul 14, 2010, 19:59 UTC · re: Will Palmer · lore

Re: [PATCHv3 1/2] add basic tests for merge-tree

Will Palmer <wmpalmer@gmail.com> writes:
Show 13 quoted lines
> merge-tree had no test cases, so here we add some very basic tests for
> it, including some known-breakages.
>
> Signed-off-by: Will Palmer <wmpalmer@gmail.com>
> ---
> diff --git a/t/t4300-merge-tree.sh b/t/t4300-merge-tree.sh
> new file mode 100755
> index 0000000..c02c986
> --- /dev/null
> +++ b/t/t4300-merge-tree.sh
> @@ -0,0 +1,257 @@
> ...
> +test_expect_'file add A, !B' '
Oops?
I'll queue with obvious/trivial fixups.  Thanks.
Will Palmer· Jul 14, 2010, 17:04 UTC · re: Will Palmer · lore

[PATCHv3 2/2] fix merge-tree where two branches share no changes

Here we fix a regression which was introduced by
15b4f7a68d8c3c8ee28424415b203f61202d65d1 /
	merge-tree: use ll_merge() not xdl_merge()

Which caused merge-tree to segfault in particular combinations of merging files which existed in one branch, but not in the other or in the merge-base. This was caused by referencing entry->path at a time when entry was known to be possibly-NULL.

To correct the problem, we save the path of the entry we came in with, as the path should be the same among all the stages no matter which sides are involved in the merge.

Signed-off-by: Will Palmer <wmpalmer@gmail.com>
---
 builtin/merge-tree.c  |    3 ++-
 t/t4300-merge-tree.sh |    6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index fc00d79..9b25ddc 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -60,6 +60,7 @@ static void *result(struct merge_list *entry, unsigned long *size)
 {
 	enum object_type type;
 	struct blob *base, *our, *their;
+	const char *path = entry->path;
 
 	if (!entry->stage)
 		return read_sha1_file(entry->blob->object.sha1, &type, size);
@@ -76,7 +77,7 @@ static void *result(struct merge_list *entry, unsigned long *size)
 	their = NULL;
 	if (entry)
 		their = entry->blob;
-	return merge_file(entry->path, base, our, their, size);
+	return merge_file(path, base, our, their, size);
 }
 
 static void *origin(struct merge_list *entry, unsigned long *size)
diff --git a/t/t4300-merge-tree.sh b/t/t4300-merge-tree.sh
index c02c986..4d0920c 100755
--- a/t/t4300-merge-tree.sh
+++ b/t/t4300-merge-tree.sh
@@ -24,7 +24,7 @@ EXPECTED
 	test_cmp expected actual
 '
 
-test_expect_failure 'file add !A, B' '
+test_expect_success 'file add !A, B' '
 	cat >expected <<\EXPECTED
 added in local
   our    100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
@@ -195,7 +195,7 @@ EXPECTED
 	test_cmp expected actual
 '
 
-test_expect_failure 'file remove !A, B' '
+test_expect_success 'file remove !A, B' '
 	cat >expected <<\EXPECTED
 removed in remote
   base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE
@@ -213,7 +213,7 @@ EXPECTED
 	test_cmp expected actual
 '
 
-test_expect_failure 'file change A, remove B' '
+test_expect_success 'file change A, remove B' '
 	cat >expected <<\EXPECTED
 removed in remote
   base   100644 43d5a8ed6ef6c00ff775008633f95787d088285d ONE

-- 
1.7.1.703.g42c01

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