From 6b1d4a4f08a45201ed42147fe9c22619f02fd2be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Mon, 6 Jan 2020 19:54:32 +0100
Subject: [PATCH] MeshTools: regression test for an OOB access in tipsify().

That was harder than I thought.
---
 src/Magnum/MeshTools/Test/TipsifyTest.cpp | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/Magnum/MeshTools/Test/TipsifyTest.cpp b/src/Magnum/MeshTools/Test/TipsifyTest.cpp
index 92ca9411d..3b7e97299 100644
--- a/src/Magnum/MeshTools/Test/TipsifyTest.cpp
+++ b/src/Magnum/MeshTools/Test/TipsifyTest.cpp
@@ -36,6 +36,7 @@ struct TipsifyTest: TestSuite::Tester {
 
     void buildAdjacency();
     void tipsify();
+    void oneDegenerateTriangle();
 };
 
 /*
@@ -82,7 +83,8 @@ constexpr std::size_t VertexCount = 19;
 
 TipsifyTest::TipsifyTest() {
     addTests({&TipsifyTest::buildAdjacency,
-              &TipsifyTest::tipsify});
+              &TipsifyTest::tipsify,
+              &TipsifyTest::oneDegenerateTriangle});
 }
 
 void TipsifyTest::buildAdjacency() {
@@ -158,6 +160,15 @@ void TipsifyTest::tipsify() {
     }));
 }
 
+void TipsifyTest::oneDegenerateTriangle() {
+    /* There used to be an OOB access (neighbors[++ti]) caught by ASan, this
+       triggers it */
+    std::vector<UnsignedInt> indices{0, 0, 0};
+    MeshTools::tipsify(indices, 1, 2);
+
+    CORRADE_COMPARE(indices, (std::vector<UnsignedInt>{0, 0, 0}));
+}
+
 }}}}
 
 CORRADE_TEST_MAIN(Magnum::MeshTools::Test::TipsifyTest)