1#!/bin/sh
2
3test_description='merge-recursive backend test'
4
5GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
6export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
7
8. ./test-lib.sh
9. "$TEST_DIRECTORY"/lib-merge.sh
10
11test_expect_success 'setup 1' '
12
13	echo hello >a &&
14	o0=$(git hash-object a) &&
15	cp a b &&
16	cp a c &&
17	mkdir d &&
18	cp a d/e &&
19
20	test_tick &&
21	git add a b c d/e &&
22	git commit -m initial &&
23	c0=$(git rev-parse --verify HEAD) &&
24	git branch side &&
25	git branch df-1 &&
26	git branch df-2 &&
27	git branch df-3 &&
28	git branch remove &&
29	git branch submod &&
30	git branch copy &&
31	git branch rename &&
32	git branch rename-ln &&
33
34	echo hello >>a &&
35	cp a d/e &&
36	o1=$(git hash-object a) &&
37
38	git add a d/e &&
39
40	test_tick &&
41	git commit -m "main modifies a and d/e" &&
42	c1=$(git rev-parse --verify HEAD) &&
43	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
44	(
45		echo "100644 blob $o1	a" &&
46		echo "100644 blob $o0	b" &&
47		echo "100644 blob $o0	c" &&
48		echo "100644 blob $o1	d/e" &&
49		echo "100644 $o1 0	a" &&
50		echo "100644 $o0 0	b" &&
51		echo "100644 $o0 0	c" &&
52		echo "100644 $o1 0	d/e"
53	) >expected &&
54	test_cmp expected actual
55'
56
57test_expect_success 'setup 2' '
58
59	rm -rf [abcd] &&
60	git checkout side &&
61	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
62	(
63		echo "100644 blob $o0	a" &&
64		echo "100644 blob $o0	b" &&
65		echo "100644 blob $o0	c" &&
66		echo "100644 blob $o0	d/e" &&
67		echo "100644 $o0 0	a" &&
68		echo "100644 $o0 0	b" &&
69		echo "100644 $o0 0	c" &&
70		echo "100644 $o0 0	d/e"
71	) >expected &&
72	test_cmp expected actual &&
73
74	echo goodbye >>a &&
75	o2=$(git hash-object a) &&
76
77	git add a &&
78
79	test_tick &&
80	git commit -m "side modifies a" &&
81	c2=$(git rev-parse --verify HEAD) &&
82	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
83	(
84		echo "100644 blob $o2	a" &&
85		echo "100644 blob $o0	b" &&
86		echo "100644 blob $o0	c" &&
87		echo "100644 blob $o0	d/e" &&
88		echo "100644 $o2 0	a" &&
89		echo "100644 $o0 0	b" &&
90		echo "100644 $o0 0	c" &&
91		echo "100644 $o0 0	d/e"
92	) >expected &&
93	test_cmp expected actual
94'
95
96test_expect_success 'setup 3' '
97
98	rm -rf [abcd] &&
99	git checkout df-1 &&
100	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
101	(
102		echo "100644 blob $o0	a" &&
103		echo "100644 blob $o0	b" &&
104		echo "100644 blob $o0	c" &&
105		echo "100644 blob $o0	d/e" &&
106		echo "100644 $o0 0	a" &&
107		echo "100644 $o0 0	b" &&
108		echo "100644 $o0 0	c" &&
109		echo "100644 $o0 0	d/e"
110	) >expected &&
111	test_cmp expected actual &&
112
113	rm -f b && mkdir b && echo df-1 >b/c && git add b/c &&
114	o3=$(git hash-object b/c) &&
115
116	test_tick &&
117	git commit -m "df-1 makes b/c" &&
118	c3=$(git rev-parse --verify HEAD) &&
119	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
120	(
121		echo "100644 blob $o0	a" &&
122		echo "100644 blob $o3	b/c" &&
123		echo "100644 blob $o0	c" &&
124		echo "100644 blob $o0	d/e" &&
125		echo "100644 $o0 0	a" &&
126		echo "100644 $o3 0	b/c" &&
127		echo "100644 $o0 0	c" &&
128		echo "100644 $o0 0	d/e"
129	) >expected &&
130	test_cmp expected actual
131'
132
133test_expect_success 'setup 4' '
134
135	rm -rf [abcd] &&
136	git checkout df-2 &&
137	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
138	(
139		echo "100644 blob $o0	a" &&
140		echo "100644 blob $o0	b" &&
141		echo "100644 blob $o0	c" &&
142		echo "100644 blob $o0	d/e" &&
143		echo "100644 $o0 0	a" &&
144		echo "100644 $o0 0	b" &&
145		echo "100644 $o0 0	c" &&
146		echo "100644 $o0 0	d/e"
147	) >expected &&
148	test_cmp expected actual &&
149
150	rm -f a && mkdir a && echo df-2 >a/c && git add a/c &&
151	o4=$(git hash-object a/c) &&
152
153	test_tick &&
154	git commit -m "df-2 makes a/c" &&
155	c4=$(git rev-parse --verify HEAD) &&
156	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
157	(
158		echo "100644 blob $o4	a/c" &&
159		echo "100644 blob $o0	b" &&
160		echo "100644 blob $o0	c" &&
161		echo "100644 blob $o0	d/e" &&
162		echo "100644 $o4 0	a/c" &&
163		echo "100644 $o0 0	b" &&
164		echo "100644 $o0 0	c" &&
165		echo "100644 $o0 0	d/e"
166	) >expected &&
167	test_cmp expected actual
168'
169
170test_expect_success 'setup 5' '
171
172	rm -rf [abcd] &&
173	git checkout remove &&
174	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
175	(
176		echo "100644 blob $o0	a" &&
177		echo "100644 blob $o0	b" &&
178		echo "100644 blob $o0	c" &&
179		echo "100644 blob $o0	d/e" &&
180		echo "100644 $o0 0	a" &&
181		echo "100644 $o0 0	b" &&
182		echo "100644 $o0 0	c" &&
183		echo "100644 $o0 0	d/e"
184	) >expected &&
185	test_cmp expected actual &&
186
187	rm -f b &&
188	echo remove-conflict >a &&
189
190	git add a &&
191	git rm b &&
192	o5=$(git hash-object a) &&
193
194	test_tick &&
195	git commit -m "remove removes b and modifies a" &&
196	c5=$(git rev-parse --verify HEAD) &&
197	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
198	(
199		echo "100644 blob $o5	a" &&
200		echo "100644 blob $o0	c" &&
201		echo "100644 blob $o0	d/e" &&
202		echo "100644 $o5 0	a" &&
203		echo "100644 $o0 0	c" &&
204		echo "100644 $o0 0	d/e"
205	) >expected &&
206	test_cmp expected actual
207
208'
209
210test_expect_success 'setup 6' '
211
212	rm -rf [abcd] &&
213	git checkout df-3 &&
214	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
215	(
216		echo "100644 blob $o0	a" &&
217		echo "100644 blob $o0	b" &&
218		echo "100644 blob $o0	c" &&
219		echo "100644 blob $o0	d/e" &&
220		echo "100644 $o0 0	a" &&
221		echo "100644 $o0 0	b" &&
222		echo "100644 $o0 0	c" &&
223		echo "100644 $o0 0	d/e"
224	) >expected &&
225	test_cmp expected actual &&
226
227	rm -fr d && echo df-3 >d && git add d &&
228	o6=$(git hash-object d) &&
229
230	test_tick &&
231	git commit -m "df-3 makes d" &&
232	c6=$(git rev-parse --verify HEAD) &&
233	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
234	(
235		echo "100644 blob $o0	a" &&
236		echo "100644 blob $o0	b" &&
237		echo "100644 blob $o0	c" &&
238		echo "100644 blob $o6	d" &&
239		echo "100644 $o0 0	a" &&
240		echo "100644 $o0 0	b" &&
241		echo "100644 $o0 0	c" &&
242		echo "100644 $o6 0	d"
243	) >expected &&
244	test_cmp expected actual
245'
246
247test_expect_success 'setup 7' '
248
249	git checkout submod &&
250	git rm d/e &&
251	test_tick &&
252	git commit -m "remove d/e" &&
253	git update-index --add --cacheinfo 160000 $c1 d &&
254	test_tick &&
255	git commit -m "make d/ a submodule"
256'
257
258test_expect_success 'setup 8' '
259	git checkout rename &&
260	git mv a e &&
261	git add e &&
262	test_tick &&
263	git commit -m "rename a->e" &&
264	c7=$(git rev-parse --verify HEAD) &&
265	git checkout rename-ln &&
266	git mv a e &&
267	test_ln_s_add e a &&
268	test_tick &&
269	git commit -m "rename a->e, symlink a->e" &&
270	oln=$(printf e | git hash-object --stdin)
271'
272
273test_expect_success 'setup 9' '
274	git checkout copy &&
275	cp a e &&
276	git add e &&
277	test_tick &&
278	git commit -m "copy a->e"
279'
280
281test_expect_success 'merge-recursive simple' '
282
283	rm -fr [abcd] &&
284	git checkout -f "$c2" &&
285
286	test_expect_code 1 git merge-recursive "$c0" -- "$c2" "$c1"
287'
288
289test_expect_success 'merge-recursive result' '
290
291	git ls-files -s >actual &&
292	(
293		echo "100644 $o0 1	a" &&
294		echo "100644 $o2 2	a" &&
295		echo "100644 $o1 3	a" &&
296		echo "100644 $o0 0	b" &&
297		echo "100644 $o0 0	c" &&
298		echo "100644 $o1 0	d/e"
299	) >expected &&
300	test_cmp expected actual
301
302'
303
304test_expect_success 'fail if the index has unresolved entries' '
305
306	rm -fr [abcd] &&
307	git checkout -f "$c1" &&
308
309	test_must_fail git merge "$c5" &&
310	test_must_fail git merge "$c5" 2> out &&
311	test_i18ngrep "not possible because you have unmerged files" out &&
312	git add -u &&
313	test_must_fail git merge "$c5" 2> out &&
314	test_i18ngrep "You have not concluded your merge" out &&
315	rm -f .git/MERGE_HEAD &&
316	test_must_fail git merge "$c5" 2> out &&
317	test_i18ngrep "Your local changes to the following files would be overwritten by merge:" out
318'
319
320test_expect_success 'merge-recursive remove conflict' '
321
322	rm -fr [abcd] &&
323	git checkout -f "$c1" &&
324
325	test_expect_code 1 git merge-recursive "$c0" -- "$c1" "$c5"
326'
327
328test_expect_success 'merge-recursive remove conflict' '
329
330	git ls-files -s >actual &&
331	(
332		echo "100644 $o0 1	a" &&
333		echo "100644 $o1 2	a" &&
334		echo "100644 $o5 3	a" &&
335		echo "100644 $o0 0	c" &&
336		echo "100644 $o1 0	d/e"
337	) >expected &&
338	test_cmp expected actual
339
340'
341
342test_expect_success 'merge-recursive d/f simple' '
343	rm -fr [abcd] &&
344	git reset --hard &&
345	git checkout -f "$c1" &&
346
347	git merge-recursive "$c0" -- "$c1" "$c3"
348'
349
350test_expect_success 'merge-recursive result' '
351
352	git ls-files -s >actual &&
353	(
354		echo "100644 $o1 0	a" &&
355		echo "100644 $o3 0	b/c" &&
356		echo "100644 $o0 0	c" &&
357		echo "100644 $o1 0	d/e"
358	) >expected &&
359	test_cmp expected actual
360
361'
362
363test_expect_success 'merge-recursive d/f conflict' '
364
365	rm -fr [abcd] &&
366	git reset --hard &&
367	git checkout -f "$c1" &&
368
369	test_expect_code 1 git merge-recursive "$c0" -- "$c1" "$c4"
370'
371
372test_expect_success 'merge-recursive d/f conflict result' '
373
374	git ls-files -s >actual &&
375	(
376		echo "100644 $o0 1	a" &&
377		echo "100644 $o1 2	a" &&
378		echo "100644 $o4 0	a/c" &&
379		echo "100644 $o0 0	b" &&
380		echo "100644 $o0 0	c" &&
381		echo "100644 $o1 0	d/e"
382	) >expected &&
383	test_cmp expected actual
384
385'
386
387test_expect_success 'merge-recursive d/f conflict the other way' '
388
389	rm -fr [abcd] &&
390	git reset --hard &&
391	git checkout -f "$c4" &&
392
393	test_expect_code 1 git merge-recursive "$c0" -- "$c4" "$c1"
394'
395
396test_expect_success 'merge-recursive d/f conflict result the other way' '
397
398	git ls-files -s >actual &&
399	(
400		echo "100644 $o0 1	a" &&
401		echo "100644 $o1 3	a" &&
402		echo "100644 $o4 0	a/c" &&
403		echo "100644 $o0 0	b" &&
404		echo "100644 $o0 0	c" &&
405		echo "100644 $o1 0	d/e"
406	) >expected &&
407	test_cmp expected actual
408
409'
410
411test_expect_success 'merge-recursive d/f conflict' '
412
413	rm -fr [abcd] &&
414	git reset --hard &&
415	git checkout -f "$c1" &&
416
417	test_expect_code 1 git merge-recursive "$c0" -- "$c1" "$c6"
418'
419
420test_expect_success 'merge-recursive d/f conflict result' '
421
422	git ls-files -s >actual &&
423	(
424		echo "100644 $o1 0	a" &&
425		echo "100644 $o0 0	b" &&
426		echo "100644 $o0 0	c" &&
427		echo "100644 $o6 3	d" &&
428		echo "100644 $o0 1	d/e" &&
429		echo "100644 $o1 2	d/e"
430	) >expected &&
431	test_cmp expected actual
432
433'
434
435test_expect_success 'merge-recursive d/f conflict' '
436
437	rm -fr [abcd] &&
438	git reset --hard &&
439	git checkout -f "$c6" &&
440
441	test_expect_code 1 git merge-recursive "$c0" -- "$c6" "$c1"
442'
443
444test_expect_success 'merge-recursive d/f conflict result' '
445
446	git ls-files -s >actual &&
447	(
448		echo "100644 $o1 0	a" &&
449		echo "100644 $o0 0	b" &&
450		echo "100644 $o0 0	c" &&
451		echo "100644 $o6 2	d" &&
452		echo "100644 $o0 1	d/e" &&
453		echo "100644 $o1 3	d/e"
454	) >expected &&
455	test_cmp expected actual
456
457'
458
459test_expect_success SYMLINKS 'dir in working tree with symlink ancestor does not produce d/f conflict' '
460	git init sym &&
461	(
462		cd sym &&
463		ln -s . foo &&
464		mkdir bar &&
465		>bar/file &&
466		git add foo bar/file &&
467		git commit -m "foo symlink" &&
468
469		git checkout -b branch1 &&
470		git commit --allow-empty -m "empty commit" &&
471
472		git checkout main &&
473		git rm foo &&
474		mkdir foo &&
475		>foo/bar &&
476		git add foo/bar &&
477		git commit -m "replace foo symlink with real foo dir and foo/bar file" &&
478
479		git checkout branch1 &&
480
481		git cherry-pick main &&
482		test_path_is_dir foo &&
483		test_path_is_file foo/bar
484	)
485'
486
487test_expect_success 'reset and 3-way merge' '
488
489	git reset --hard "$c2" &&
490	git read-tree -m "$c0" "$c2" "$c1"
491
492'
493
494test_expect_success 'reset and bind merge' '
495
496	git reset --hard main &&
497	git read-tree --prefix=M/ main &&
498	git ls-files -s >actual &&
499	(
500		echo "100644 $o1 0	M/a" &&
501		echo "100644 $o0 0	M/b" &&
502		echo "100644 $o0 0	M/c" &&
503		echo "100644 $o1 0	M/d/e" &&
504		echo "100644 $o1 0	a" &&
505		echo "100644 $o0 0	b" &&
506		echo "100644 $o0 0	c" &&
507		echo "100644 $o1 0	d/e"
508	) >expected &&
509	test_cmp expected actual &&
510
511	git read-tree --prefix=a1/ main &&
512	git ls-files -s >actual &&
513	(
514		echo "100644 $o1 0	M/a" &&
515		echo "100644 $o0 0	M/b" &&
516		echo "100644 $o0 0	M/c" &&
517		echo "100644 $o1 0	M/d/e" &&
518		echo "100644 $o1 0	a" &&
519		echo "100644 $o1 0	a1/a" &&
520		echo "100644 $o0 0	a1/b" &&
521		echo "100644 $o0 0	a1/c" &&
522		echo "100644 $o1 0	a1/d/e" &&
523		echo "100644 $o0 0	b" &&
524		echo "100644 $o0 0	c" &&
525		echo "100644 $o1 0	d/e"
526	) >expected &&
527	test_cmp expected actual &&
528
529	git read-tree --prefix=z/ main &&
530	git ls-files -s >actual &&
531	(
532		echo "100644 $o1 0	M/a" &&
533		echo "100644 $o0 0	M/b" &&
534		echo "100644 $o0 0	M/c" &&
535		echo "100644 $o1 0	M/d/e" &&
536		echo "100644 $o1 0	a" &&
537		echo "100644 $o1 0	a1/a" &&
538		echo "100644 $o0 0	a1/b" &&
539		echo "100644 $o0 0	a1/c" &&
540		echo "100644 $o1 0	a1/d/e" &&
541		echo "100644 $o0 0	b" &&
542		echo "100644 $o0 0	c" &&
543		echo "100644 $o1 0	d/e" &&
544		echo "100644 $o1 0	z/a" &&
545		echo "100644 $o0 0	z/b" &&
546		echo "100644 $o0 0	z/c" &&
547		echo "100644 $o1 0	z/d/e"
548	) >expected &&
549	test_cmp expected actual
550
551'
552
553test_expect_success 'merge-recursive w/ empty work tree - ours has rename' '
554	(
555		GIT_WORK_TREE="$PWD/ours-has-rename-work" &&
556		export GIT_WORK_TREE &&
557		GIT_INDEX_FILE="$PWD/ours-has-rename-index" &&
558		export GIT_INDEX_FILE &&
559		mkdir "$GIT_WORK_TREE" &&
560		git read-tree -i -m $c7 2>actual-err &&
561		test_must_be_empty actual-err &&
562		git update-index --ignore-missing --refresh 2>actual-err &&
563		test_must_be_empty actual-err &&
564		git merge-recursive $c0 -- $c7 $c3 2>actual-err &&
565		test_must_be_empty actual-err &&
566		git ls-files -s >actual-files 2>actual-err &&
567		test_must_be_empty actual-err
568	) &&
569	cat >expected-files <<-EOF &&
570	100644 $o3 0	b/c
571	100644 $o0 0	c
572	100644 $o0 0	d/e
573	100644 $o0 0	e
574	EOF
575	test_cmp expected-files actual-files
576'
577
578test_expect_success 'merge-recursive w/ empty work tree - theirs has rename' '
579	(
580		GIT_WORK_TREE="$PWD/theirs-has-rename-work" &&
581		export GIT_WORK_TREE &&
582		GIT_INDEX_FILE="$PWD/theirs-has-rename-index" &&
583		export GIT_INDEX_FILE &&
584		mkdir "$GIT_WORK_TREE" &&
585		git read-tree -i -m $c3 2>actual-err &&
586		test_must_be_empty actual-err &&
587		git update-index --ignore-missing --refresh 2>actual-err &&
588		test_must_be_empty actual-err &&
589		git merge-recursive $c0 -- $c3 $c7 2>actual-err &&
590		test_must_be_empty actual-err &&
591		git ls-files -s >actual-files 2>actual-err &&
592		test_must_be_empty actual-err
593	) &&
594	cat >expected-files <<-EOF &&
595	100644 $o3 0	b/c
596	100644 $o0 0	c
597	100644 $o0 0	d/e
598	100644 $o0 0	e
599	EOF
600	test_cmp expected-files actual-files
601'
602
603test_expect_success 'merge removes empty directories' '
604
605	git reset --hard main &&
606	git checkout -b rm &&
607	git rm d/e &&
608	git commit -mremoved-d/e &&
609	git checkout main &&
610	git merge -s recursive rm &&
611	test_path_is_missing d
612'
613
614test_expect_success 'merge-recursive simple w/submodule' '
615
616	git checkout submod &&
617	git merge remove
618'
619
620test_expect_success 'merge-recursive simple w/submodule result' '
621
622	git ls-files -s >actual &&
623	(
624		echo "100644 $o5 0	a" &&
625		echo "100644 $o0 0	c" &&
626		echo "160000 $c1 0	d"
627	) >expected &&
628	test_cmp expected actual
629'
630
631test_expect_success 'merge-recursive copy vs. rename' '
632	git checkout -f copy &&
633	git merge rename &&
634	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
635	(
636		echo "100644 blob $o0	b" &&
637		echo "100644 blob $o0	c" &&
638		echo "100644 blob $o0	d/e" &&
639		echo "100644 blob $o0	e" &&
640		echo "100644 $o0 0	b" &&
641		echo "100644 $o0 0	c" &&
642		echo "100644 $o0 0	d/e" &&
643		echo "100644 $o0 0	e"
644	) >expected &&
645	test_cmp expected actual
646'
647
648test_expect_merge_algorithm failure success 'merge-recursive rename vs. rename/symlink' '
649
650	git checkout -f rename &&
651	git merge rename-ln &&
652	( git ls-tree -r HEAD && git ls-files -s ) >actual &&
653	(
654		echo "120000 blob $oln	a" &&
655		echo "100644 blob $o0	b" &&
656		echo "100644 blob $o0	c" &&
657		echo "100644 blob $o0	d/e" &&
658		echo "100644 blob $o0	e" &&
659		echo "120000 $oln 0	a" &&
660		echo "100644 $o0 0	b" &&
661		echo "100644 $o0 0	c" &&
662		echo "100644 $o0 0	d/e" &&
663		echo "100644 $o0 0	e"
664	) >expected &&
665	test_cmp expected actual
666'
667
668test_expect_success 'merging with triple rename across D/F conflict' '
669	git reset --hard HEAD &&
670	git checkout -b topic &&
671	git rm -rf . &&
672
673	echo "just a file" >sub1 &&
674	mkdir -p sub2 &&
675	echo content1 >sub2/file1 &&
676	echo content2 >sub2/file2 &&
677	echo content3 >sub2/file3 &&
678	mkdir simple &&
679	echo base >simple/bar &&
680	git add -A &&
681	test_tick &&
682	git commit -m base &&
683
684	git checkout -b other &&
685	echo more >>simple/bar &&
686	test_tick &&
687	git commit -a -m changesimplefile &&
688
689	git checkout topic &&
690	git rm sub1 &&
691	git mv sub2 sub1 &&
692	test_tick &&
693	git commit -m changefiletodir &&
694
695	test_tick &&
696	git merge other
697'
698
699test_expect_success 'merge-recursive remembers the names of all base trees' '
700	git reset --hard HEAD &&
701
702	# make the index match $c1 so that merge-recursive below does not
703	# fail early
704	git diff --binary HEAD $c1 -- | git apply --cached &&
705
706	# more trees than static slots used by oid_to_hex()
707	for commit in $c0 $c2 $c4 $c5 $c6 $c7
708	do
709		git rev-parse "$commit^{tree}"
710	done >trees &&
711
712	# ignore the return code; it only fails because the input is weird...
713	test_must_fail git -c merge.verbosity=5 merge-recursive $(cat trees) -- $c1 $c3 >out &&
714
715	# ...but make sure it fails in the expected way
716	test_i18ngrep CONFLICT.*rename/rename out &&
717
718	# merge-recursive prints in reverse order, but we do not care
719	sort <trees >expect &&
720	sed -n "s/^virtual //p" out | sort >actual &&
721	test_cmp expect actual &&
722
723	git clean -fd
724'
725
726test_expect_success 'merge-recursive internal merge resolves to the sameness' '
727	git reset --hard HEAD &&
728
729	# We are going to create a history leading to two criss-cross
730	# branches A and B.  The common ancestor at the bottom, O0,
731	# has two child commits O1 and O2, both of which will be merge
732	# base between A and B, like so:
733	#
734	#       O1---A
735	#      /  \ /
736	#    O0    .
737	#      \  / \
738	#       O2---B
739	#
740	# The recently added "check to see if the index is different from
741	# the tree into which something else is getting merged" check must
742	# NOT kick in when an inner merge between O1 and O2 is made.  Both
743	# O1 and O2 happen to have the same tree as O0 in this test to
744	# trigger the bug---whether the inner merge is made by merging O2
745	# into O1 or O1 into O2, their common ancestor O0 and the branch
746	# being merged have the same tree.  We should not trigger the "is
747	# the index dirty?" check in this case.
748
749	echo "zero" >file &&
750	git add file &&
751	test_tick &&
752	git commit -m "O0" &&
753	O0=$(git rev-parse HEAD) &&
754
755	test_tick &&
756	git commit --allow-empty -m "O1" &&
757	O1=$(git rev-parse HEAD) &&
758
759	git reset --hard $O0 &&
760	test_tick &&
761	git commit --allow-empty -m "O2" &&
762	O2=$(git rev-parse HEAD) &&
763
764	test_tick &&
765	git merge -s ours $O1 &&
766	B=$(git rev-parse HEAD) &&
767
768	git reset --hard $O1 &&
769	test_tick &&
770	git merge -s ours $O2 &&
771	A=$(git rev-parse HEAD) &&
772
773	git merge $B
774'
775
776test_done
777