Subject: [PATCH v4 15/21] commit-graph: test for corrupted octopus edge

From: Derrick Stolee <[email-masked]>
Date: Mon, 4 Jun 2018 16:52:48 +0000

The commit-graph file has an extra chunk to store the parent int-ids for
parents beyond the first parent for octopus merges. Our test repo has a
single octopus merge that we can manipulate to demonstrate the 'verify'
subcommand detects incorrect values in that chunk.

Signed-off-by: Derrick Stolee <[email-masked]>
---
 t/t5318-commit-graph.sh | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 6a873bfda8..cf67fb391a 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -248,6 +248,7 @@ test_expect_success 'git commit-graph verify' '
 '
 
 NUM_COMMITS=9
+NUM_OCTOPUS_EDGES=2
 HASH_LEN=20
 GRAPH_BYTE_VERSION=4
 GRAPH_BYTE_HASH=5
@@ -274,6 +275,10 @@ GRAPH_BYTE_COMMIT_EXTRA_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 4))
 GRAPH_BYTE_COMMIT_WRONG_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 3))
 GRAPH_BYTE_COMMIT_GENERATION=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 11))
 GRAPH_BYTE_COMMIT_DATE=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 12))
+GRAPH_COMMIT_DATA_WIDTH=$(($HASH_LEN + 16))
+GRAPH_OCTOPUS_DATA_OFFSET=$(($GRAPH_COMMIT_DATA_OFFSET + \
+			     $GRAPH_COMMIT_DATA_WIDTH \* $NUM_COMMITS))
+GRAPH_BYTE_OCTOPUS=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4))
 
 # usage: corrupt_graph_and_verify <position> <data> <string>
 # Manipulates the commit-graph file at the position
@@ -383,4 +388,9 @@ test_expect_success 'detect incorrect commit date' '
 		"commit date"
 '
 
+test_expect_success 'detect incorrect parent for octopus merge' '
+	corrupt_graph_and_verify $GRAPH_BYTE_OCTOPUS "\01" \
+		"invalid parent"
+'
+
 test_done
-- 
2.18.0.rc1