From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 21 Nov 2018 13:57:46 +0000 (+0900)
Subject: Merge branch 'tg/range-diff-corner-case-fix' into maint
X-Git-Tag: v2.19.2~54
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/a357daeac6b95fa50b80404859d916c71320b79c?hp=50e6df214d7f75559e4ad90c2fd1d8fc36938c8c

Merge branch 'tg/range-diff-corner-case-fix' into maint

Recently added "range-diff" had a corner-case bug to cause it
segfault, which has been corrected.

* tg/range-diff-corner-case-fix:
linear-assignment: fix potential out of bounds memory access
---

diff --git a/linear-assignment.c b/linear-assignment.c
index 9b3e56e283..ecffc09be6 100644
--- a/linear-assignment.c
+++ b/linear-assignment.c
@@ -19,6 +19,12 @@ void compute_assignment(int column_count, int row_count, int *cost,
 	int *free_row, free_count = 0, saved_free_count, *pred, *col;
 	int i, j, phase;
 
+	if (column_count < 2) {
+		memset(column2row, 0, sizeof(int) * column_count);
+		memset(row2column, 0, sizeof(int) * row_count);
+		return;
+	}
+
 	memset(column2row, -1, sizeof(int) * column_count);
 	memset(row2column, -1, sizeof(int) * row_count);
 	ALLOC_ARRAY(v, column_count);
diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index 2237c7f4af..fb4c13a84a 100755
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -142,4 +142,9 @@ test_expect_success 'changed message' '
 	test_cmp expected actual
 '
 
+test_expect_success 'no commits on one side' '
+	git commit --amend -m "new message" &&
+	git range-diff master HEAD@{1} HEAD
+'
+
 test_done