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[BUG/PATCH 5/5] t4214: demonstrate octopus graph coloring failure

From
Denton Liu <liu.denton@gmail.com>
Date
Sep 25, 2019, 10:27 UTC
Message-ID
<0b84bf54175cd8ee967ab46ac393c2d5d18d772e.1569407150.git.liu.denton@gmail.com>
In-Reply-To
<cover.1569407150.git.liu.denton@gmail.com>

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 two sets of test cases. The first pair of test cases demonstrates the breakage with a similar case as the above. The second pair of test cases demonstrates a similar breakage but with the last parent crossing over.

The second pair of test cases are included as a result of my (poor) attempts at fixing the bug. This case seems particularly tricky to handle. Good luck!

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 t/t4214-log-graph-octopus.sh | 96 +++++++++++++++++++++++++++++++++++-
 1 file changed, 95 insertions(+), 1 deletion(-)
diff --git a/t/t4214-log-graph-octopus.sh b/t/t4214-log-graph-octopus.sh
index 097151da39..99e0ea034e 100755
--- a/t/t4214-log-graph-octopus.sh
+++ b/t/t4214-log-graph-octopus.sh
@@ -14,8 +14,11 @@ 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
 '
 
 test_expect_success 'log --graph with tricky octopus merge, no color' '
@@ -98,4 +101,95 @@ 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 tricky octopus merge and its parent, 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 parent 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_done

-- 
2.23.0.248.g3a9dd8fb08
Previous: Denton LiuNext: Denton Liu
Message 6 of 16 in “t4214: cleanup and demonstrate graph bug”
  1. 0/5 t4214: cleanup and demonstrate graph bugDenton Liu, Sep 25, 2019
  2. 1/5 test-lib: let test_merge() perform octopus mergesDenton Liu, Sep 25, 2019
  3. 2/5 t4214: use test_mergeDenton Liu, Sep 25, 2019
  4. 3/5 t4214: generate expect in their own test casesDenton Liu, Sep 25, 2019
  5. 4/5 t4214: explicitly list tags in logDenton Liu, Sep 25, 2019
  6. 5/5 t4214: demonstrate octopus graph coloring failureDenton Liu, Sep 25, 2019
  7. Denton LiuSep 25, 2019
  8. Jeff KingSep 26, 2019
  9. Junio C HamanoOct 3, 2019
  10. 0/5 t4214: cleanup and demonstrate graph bugDenton Liu, Oct 4, 2019
  11. 1/5 test-lib: let test_merge() perform octopus mergesDenton Liu, Oct 4, 2019
  12. 4/5 t4214: explicitly list tags in logDenton Liu, Oct 4, 2019
  13. 2/5 t4214: use test_mergeDenton Liu, Oct 4, 2019
  14. 3/5 t4214: generate expect in their own test casesDenton Liu, Oct 4, 2019
  15. 5/5 t4214: demonstrate octopus graph coloring failureDenton Liu, Oct 4, 2019
  16. Junio C HamanoOct 4, 2019

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