t4214: demonstrate octopus graph coloring failure

The graph coloring logic for octopus merges currently has a bug. This
can be seen git.git with 74c7cfa875 (Merge of
http://members.cox.net/junkio/git-jc.git, 2005-05-05), whose second
child is 211232bae6 (Octopus merge of the following five patches.,
2005-05-05).

If one runs

	git log --graph 74c7cfa875

one can see that the octopus merge is colored incorrectly. In
particular, the horizontal dashes are off by one color. Each horizontal
dash should be the color of the line to their bottom-right. Instead, they
are currently the color of the line to their bottom.

Demonstrate this breakage with a few sets of test cases. These test
cases should show not only simple cases of the bug occuring but trickier
situations that may not be handled properly in any attempt to fix the
bug.

While we're at it, include a passing test case as a canary in case an
attempt to fix the bug breaks existing operation.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 281 insertions, 1 deletions

diff --git a/t/t4214-log-graph-octopus.sh b/t/t4214-log-graph-octopus.sh
index 097151da39..3ae8e51e50 100755
--- a/t/t4214-log-graph-octopus.sh
+++ b/t/t4214-log-graph-octopus.sh
@@ -14,8 +14,13 @@ test_expect_success 'set up merge history' '
 	done &&
 	git checkout 1 -b merge &&
 	test_merge octopus-merge 1 2 3 4 &&
+	test_commit after-merge &&
 	git checkout 1 -b L &&
-	test_commit left
+	test_commit left &&
+	git checkout 4 -b crossover &&
+	test_commit after-4 &&
+	git checkout initial -b more-L &&
+	test_commit after-initial
 '
 
 test_expect_success 'log --graph with tricky octopus merge, no color' '
@@ -98,4 +103,279 @@ test_expect_success 'log --graph with normal octopus merge with colors' '
 	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
 	test_cmp expect.colors actual.colors
 '
+
+test_expect_success 'log --graph with normal octopus merge and child, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* after-merge
+	*---.   octopus-merge
+	|\ \ \
+	| | | * 4
+	| | * | 3
+	| | |/
+	| * | 2
+	| |/
+	* | 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s after-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_failure 'log --graph with normal octopus and child merge with colors' '
+	cat >expect.colors <<-\EOF &&
+	* after-merge
+	*<BLUE>-<RESET><BLUE>-<RESET><MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
+	<GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <MAGENTA>\<RESET>
+	<GREEN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> * 4
+	<GREEN>|<RESET> <YELLOW>|<RESET> * <MAGENTA>|<RESET> 3
+	<GREEN>|<RESET> <YELLOW>|<RESET> <MAGENTA>|<RESET><MAGENTA>/<RESET>
+	<GREEN>|<RESET> * <MAGENTA>|<RESET> 2
+	<GREEN>|<RESET> <MAGENTA>|<RESET><MAGENTA>/<RESET>
+	* <MAGENTA>|<RESET> 1
+	<MAGENTA>|<RESET><MAGENTA>/<RESET>
+	* initial
+	EOF
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	git log --color=always --graph --date-order --pretty=tformat:%s after-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with tricky octopus merge and its child, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* left
+	| * after-merge
+	| *---.   octopus-merge
+	| |\ \ \
+	|/ / / /
+	| | | * 4
+	| | * | 3
+	| | |/
+	| * | 2
+	| |/
+	* | 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s left after-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_failure 'log --graph with tricky octopus merge and its child with colors' '
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	cat >expect.colors <<-\EOF &&
+	* left
+	<RED>|<RESET> * after-merge
+	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>-<RESET><CYAN>-<RESET><CYAN>.<RESET>   octopus-merge
+	<RED>|<RESET> <RED>|<RESET><BLUE>\<RESET> <MAGENTA>\<RESET> <CYAN>\<RESET>
+	<RED>|<RESET><RED>/<RESET> <BLUE>/<RESET> <MAGENTA>/<RESET> <CYAN>/<RESET>
+	<RED>|<RESET> <BLUE>|<RESET> <MAGENTA>|<RESET> * 4
+	<RED>|<RESET> <BLUE>|<RESET> * <CYAN>|<RESET> 3
+	<RED>|<RESET> <BLUE>|<RESET> <CYAN>|<RESET><CYAN>/<RESET>
+	<RED>|<RESET> * <CYAN>|<RESET> 2
+	<RED>|<RESET> <CYAN>|<RESET><CYAN>/<RESET>
+	* <CYAN>|<RESET> 1
+	<CYAN>|<RESET><CYAN>/<RESET>
+	* initial
+	EOF
+	git log --color=always --graph --date-order --pretty=tformat:%s left after-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with crossover in octopus merge, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* after-4
+	| *---.   octopus-merge
+	| |\ \ \
+	| |_|_|/
+	|/| | |
+	* | | | 4
+	| | | * 3
+	| |_|/
+	|/| |
+	| | * 2
+	| |/
+	|/|
+	| * 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s after-4 octopus-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_failure 'log --graph with crossover in octopus merge with colors' '
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	cat >expect.colors <<-\EOF &&
+	* after-4
+	<RED>|<RESET> *<BLUE>-<RESET><BLUE>-<RESET><RED>-<RESET><RED>.<RESET>   octopus-merge
+	<RED>|<RESET> <GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <RED>\<RESET>
+	<RED>|<RESET> <GREEN>|<RESET><RED>_<RESET><YELLOW>|<RESET><RED>_<RESET><BLUE>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><GREEN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET>
+	* <GREEN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> 4
+	<MAGENTA>|<RESET> <GREEN>|<RESET> <YELLOW>|<RESET> * 3
+	<MAGENTA>|<RESET> <GREEN>|<RESET><MAGENTA>_<RESET><YELLOW>|<RESET><MAGENTA>/<RESET>
+	<MAGENTA>|<RESET><MAGENTA>/<RESET><GREEN>|<RESET> <YELLOW>|<RESET>
+	<MAGENTA>|<RESET> <GREEN>|<RESET> * 2
+	<MAGENTA>|<RESET> <GREEN>|<RESET><MAGENTA>/<RESET>
+	<MAGENTA>|<RESET><MAGENTA>/<RESET><GREEN>|<RESET>
+	<MAGENTA>|<RESET> * 1
+	<MAGENTA>|<RESET><MAGENTA>/<RESET>
+	* initial
+	EOF
+	git log --color=always --graph --date-order --pretty=tformat:%s after-4 octopus-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with crossover in octopus merge and its child, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* after-4
+	| * after-merge
+	| *---.   octopus-merge
+	| |\ \ \
+	| |_|_|/
+	|/| | |
+	* | | | 4
+	| | | * 3
+	| |_|/
+	|/| |
+	| | * 2
+	| |/
+	|/|
+	| * 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s after-4 after-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_failure 'log --graph with crossover in octopus merge and its child with colors' '
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	cat >expect.colors <<-\EOF &&
+	* after-4
+	<RED>|<RESET> * after-merge
+	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>-<RESET><RED>-<RESET><RED>.<RESET>   octopus-merge
+	<RED>|<RESET> <YELLOW>|<RESET><BLUE>\<RESET> <MAGENTA>\<RESET> <RED>\<RESET>
+	<RED>|<RESET> <YELLOW>|<RESET><RED>_<RESET><BLUE>|<RESET><RED>_<RESET><MAGENTA>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><YELLOW>|<RESET> <BLUE>|<RESET> <MAGENTA>|<RESET>
+	* <YELLOW>|<RESET> <BLUE>|<RESET> <MAGENTA>|<RESET> 4
+	<CYAN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> * 3
+	<CYAN>|<RESET> <YELLOW>|<RESET><CYAN>_<RESET><BLUE>|<RESET><CYAN>/<RESET>
+	<CYAN>|<RESET><CYAN>/<RESET><YELLOW>|<RESET> <BLUE>|<RESET>
+	<CYAN>|<RESET> <YELLOW>|<RESET> * 2
+	<CYAN>|<RESET> <YELLOW>|<RESET><CYAN>/<RESET>
+	<CYAN>|<RESET><CYAN>/<RESET><YELLOW>|<RESET>
+	<CYAN>|<RESET> * 1
+	<CYAN>|<RESET><CYAN>/<RESET>
+	* initial
+	EOF
+	git log --color=always --graph --date-order --pretty=tformat:%s after-4 after-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with unrelated commit and octopus tip, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* after-initial
+	| *---.   octopus-merge
+	| |\ \ \
+	| | | | * 4
+	| |_|_|/
+	|/| | |
+	| | | * 3
+	| |_|/
+	|/| |
+	| | * 2
+	| |/
+	|/|
+	| * 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s after-initial octopus-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_success 'log --graph with unrelated commit and octopus tip with colors' '
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	cat >expect.colors <<-\EOF &&
+	* after-initial
+	<RED>|<RESET> *<BLUE>-<RESET><BLUE>-<RESET><MAGENTA>-<RESET><MAGENTA>.<RESET>   octopus-merge
+	<RED>|<RESET> <GREEN>|<RESET><YELLOW>\<RESET> <BLUE>\<RESET> <MAGENTA>\<RESET>
+	<RED>|<RESET> <GREEN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> * 4
+	<RED>|<RESET> <GREEN>|<RESET><RED>_<RESET><YELLOW>|<RESET><RED>_<RESET><BLUE>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><GREEN>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET>
+	<RED>|<RESET> <GREEN>|<RESET> <YELLOW>|<RESET> * 3
+	<RED>|<RESET> <GREEN>|<RESET><RED>_<RESET><YELLOW>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><GREEN>|<RESET> <YELLOW>|<RESET>
+	<RED>|<RESET> <GREEN>|<RESET> * 2
+	<RED>|<RESET> <GREEN>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><GREEN>|<RESET>
+	<RED>|<RESET> * 1
+	<RED>|<RESET><RED>/<RESET>
+	* initial
+	EOF
+	git log --color=always --graph --date-order --pretty=tformat:%s after-initial octopus-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
+test_expect_success 'log --graph with unrelated commit and octopus child, no color' '
+	cat >expect.uncolored <<-\EOF &&
+	* after-initial
+	| * after-merge
+	| *---.   octopus-merge
+	| |\ \ \
+	| | | | * 4
+	| |_|_|/
+	|/| | |
+	| | | * 3
+	| |_|/
+	|/| |
+	| | * 2
+	| |/
+	|/|
+	| * 1
+	|/
+	* initial
+	EOF
+	git log --color=never --graph --date-order --pretty=tformat:%s after-initial after-merge >actual.raw &&
+	sed "s/ *\$//" actual.raw >actual &&
+	test_cmp expect.uncolored actual
+'
+
+test_expect_failure 'log --graph with unrelated commit and octopus child with colors' '
+	test_config log.graphColors red,green,yellow,blue,magenta,cyan &&
+	cat >expect.colors <<-\EOF &&
+	* after-initial
+	<RED>|<RESET> * after-merge
+	<RED>|<RESET> *<MAGENTA>-<RESET><MAGENTA>-<RESET><CYAN>-<RESET><CYAN>.<RESET>   octopus-merge
+	<RED>|<RESET> <YELLOW>|<RESET><BLUE>\<RESET> <MAGENTA>\<RESET> <CYAN>\<RESET>
+	<RED>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> <MAGENTA>|<RESET> * 4
+	<RED>|<RESET> <YELLOW>|<RESET><RED>_<RESET><BLUE>|<RESET><RED>_<RESET><MAGENTA>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><YELLOW>|<RESET> <BLUE>|<RESET> <MAGENTA>|<RESET>
+	<RED>|<RESET> <YELLOW>|<RESET> <BLUE>|<RESET> * 3
+	<RED>|<RESET> <YELLOW>|<RESET><RED>_<RESET><BLUE>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><YELLOW>|<RESET> <BLUE>|<RESET>
+	<RED>|<RESET> <YELLOW>|<RESET> * 2
+	<RED>|<RESET> <YELLOW>|<RESET><RED>/<RESET>
+	<RED>|<RESET><RED>/<RESET><YELLOW>|<RESET>
+	<RED>|<RESET> * 1
+	<RED>|<RESET><RED>/<RESET>
+	* initial
+	EOF
+	git log --color=always --graph --date-order --pretty=tformat:%s after-initial after-merge >actual.colors.raw &&
+	test_decode_color <actual.colors.raw | sed "s/ *\$//" >actual.colors &&
+	test_cmp expect.colors actual.colors
+'
+
 test_done