t3034: add rename threshold tests

10ae752 (merge-recursive: option to specify rename threshold,
2010-09-27) introduced this feature but did not include any tests.

The tests use the new option --find-renames, which replaces the then
introduced and now deprecated option --rename-threshold.

Also update name and description of t3032 for consistency:
"merge-recursive options" -> "merge-recursive space options"

Signed-off-by: Felipe Gonçalves Assis <felipegassis@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3032-merge-recursive-options.sh → t/t3032-merge-recursive-space-options.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='merge-recursive options
+test_description='merge-recursive space options
 
 * [master] Clarify
  ! [remote] Remove cruft

t/t3034-merge-recursive-rename-options.sh

@@ -0,0 +1,238 @@
+#!/bin/sh
+
+test_description='merge-recursive rename options
+
+Test rename detection by examining rename/delete conflicts.
+
+* (HEAD -> rename) rename
+| * (master) delete
+|/
+* base
+
+git diff --name-status base master
+D	0-old
+D	1-old
+D	2-old
+D	3-old
+
+git diff --name-status -M01 base rename
+R025    0-old   0-new
+R050    1-old   1-new
+R075    2-old   2-new
+R100    3-old   3-new
+
+Actual similarity indices are parsed from diff output. We rely on the fact that
+they are rounded down (see, e.g., Documentation/diff-generate-patch.txt, which
+mentions this in a different context).
+'
+
+. ./test-lib.sh
+
+get_expected_stages () {
+	git checkout rename -- $1-new &&
+	git ls-files --stage $1-new >expected-stages-undetected-$1 &&
+	sed "s/ 0	/ 2	/" <expected-stages-undetected-$1 \
+		>expected-stages-detected-$1 &&
+	git read-tree -u --reset HEAD
+}
+
+rename_detected () {
+	git ls-files --stage $1-old $1-new >stages-actual-$1 &&
+	test_cmp expected-stages-detected-$1 stages-actual-$1
+}
+
+rename_undetected () {
+	git ls-files --stage $1-old $1-new >stages-actual-$1 &&
+	test_cmp expected-stages-undetected-$1 stages-actual-$1
+}
+
+check_common () {
+	git ls-files --stage >stages-actual &&
+	test_line_count = 4 stages-actual
+}
+
+check_threshold_0 () {
+	check_common &&
+	rename_detected 0 &&
+	rename_detected 1 &&
+	rename_detected 2 &&
+	rename_detected 3
+}
+
+check_threshold_1 () {
+	check_common &&
+	rename_undetected 0 &&
+	rename_detected 1 &&
+	rename_detected 2 &&
+	rename_detected 3
+}
+
+check_threshold_2 () {
+	check_common &&
+	rename_undetected 0 &&
+	rename_undetected 1 &&
+	rename_detected 2 &&
+	rename_detected 3
+}
+
+check_exact_renames () {
+	check_common &&
+	rename_undetected 0 &&
+	rename_undetected 1 &&
+	rename_undetected 2 &&
+	rename_detected 3
+}
+
+test_expect_success 'setup repo' '
+	cat <<-\EOF >3-old &&
+	33a
+	33b
+	33c
+	33d
+	EOF
+	sed s/33/22/ <3-old >2-old &&
+	sed s/33/11/ <3-old >1-old &&
+	sed s/33/00/ <3-old >0-old &&
+	git add [0-3]-old &&
+	git commit -m base &&
+	git rm [0-3]-old &&
+	git commit -m delete &&
+	git checkout -b rename HEAD^ &&
+	cp 3-old 3-new &&
+	sed 1,1s/./x/ <2-old >2-new &&
+	sed 1,2s/./x/ <1-old >1-new &&
+	sed 1,3s/./x/ <0-old >0-new &&
+	git add [0-3]-new &&
+	git rm [0-3]-old &&
+	git commit -m rename &&
+	get_expected_stages 0 &&
+	get_expected_stages 1 &&
+	get_expected_stages 2 &&
+	get_expected_stages 3 &&
+	check_50="false" &&
+	tail="HEAD^ -- HEAD master"
+'
+
+test_expect_success 'setup thresholds' '
+	git diff --name-status -M01 HEAD^ HEAD >diff-output &&
+	test_debug "cat diff-output" &&
+	test_line_count = 4 diff-output &&
+	grep "R[0-9][0-9][0-9]	\([0-3]\)-old	\1-new" diff-output \
+		>grep-output &&
+	test_cmp diff-output grep-output &&
+	th0=$(sed -n "s/R\(...\)	0-old	0-new/\1/p" <diff-output) &&
+	th1=$(sed -n "s/R\(...\)	1-old	1-new/\1/p" <diff-output) &&
+	th2=$(sed -n "s/R\(...\)	2-old	2-new/\1/p" <diff-output) &&
+	th3=$(sed -n "s/R\(...\)	3-old	3-new/\1/p" <diff-output) &&
+	test "$th0" -lt "$th1" &&
+	test "$th1" -lt "$th2" &&
+	test "$th2" -lt "$th3" &&
+	test "$th3" = 100 &&
+	if test 50 -le "$th0"
+	then
+		check_50=check_threshold_0
+	elif test 50 -le "$th1"
+	then
+		check_50=check_threshold_1
+	elif test 50 -le "$th2"
+	then
+		check_50=check_threshold_2
+	fi &&
+	th0="$th0%" &&
+	th1="$th1%" &&
+	th2="$th2%" &&
+	th3="$th3%"
+'
+
+test_expect_success 'assumption for tests: rename detection with diff' '
+	git diff --name-status -M$th0 --diff-filter=R HEAD^ HEAD \
+		>diff-output-0 &&
+	git diff --name-status -M$th1 --diff-filter=R HEAD^ HEAD \
+		>diff-output-1 &&
+	git diff --name-status -M$th2 --diff-filter=R HEAD^ HEAD \
+		>diff-output-2 &&
+	git diff --name-status -M100% --diff-filter=R HEAD^ HEAD \
+		>diff-output-3 &&
+	test_line_count = 4 diff-output-0 &&
+	test_line_count = 3 diff-output-1 &&
+	test_line_count = 2 diff-output-2 &&
+	test_line_count = 1 diff-output-3
+'
+
+test_expect_success 'default similarity threshold is 50%' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive $tail &&
+	$check_50
+'
+
+test_expect_success 'low rename threshold' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=$th0 $tail &&
+	check_threshold_0
+'
+
+test_expect_success 'medium rename threshold' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=$th1 $tail &&
+	check_threshold_1
+'
+
+test_expect_success 'high rename threshold' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=$th2 $tail &&
+	check_threshold_2
+'
+
+test_expect_success 'exact renames only' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=100% $tail &&
+	check_exact_renames
+'
+
+test_expect_success 'rename threshold is truncated' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=200% $tail &&
+	check_exact_renames
+'
+
+test_expect_success 'last wins in --find-renames=<m> --find-renames=<n>' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive \
+		--find-renames=$th0 --find-renames=$th2 $tail &&
+	check_threshold_2
+'
+
+test_expect_success '--find-renames resets threshold' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive \
+		--find-renames=$th0 --find-renames $tail &&
+	$check_50
+'
+
+test_expect_success 'assumption for further tests: trivial merge succeeds' '
+	git read-tree --reset -u HEAD &&
+	git merge-recursive HEAD -- HEAD HEAD &&
+	git diff --quiet --cached &&
+	git merge-recursive --find-renames=$th0 HEAD -- HEAD HEAD &&
+	git diff --quiet --cached &&
+	git merge-recursive --find-renames=$th2 HEAD -- HEAD HEAD &&
+	git diff --quiet --cached &&
+	git merge-recursive --find-renames=100% HEAD -- HEAD HEAD &&
+	git diff --quiet --cached
+'
+
+test_expect_success '--find-renames rejects negative argument' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=-25 \
+		HEAD -- HEAD HEAD &&
+	git diff --quiet --cached
+'
+
+test_expect_success '--find-renames rejects non-numbers' '
+	git read-tree --reset -u HEAD &&
+	test_must_fail git merge-recursive --find-renames=0xf \
+		HEAD -- HEAD HEAD &&
+	git diff --quiet --cached
+'
+
+test_done