1 files changed, 66 insertions, 0 deletions
diff --git a/core/fpdfapi/page/cpdf_pageobjectholder_unittest.cpp b/core/fpdfapi/page/cpdf_pageobjectholder_unittest.cpp
new file mode 100644
index 0000000000..ddad795fea
--- /dev/null
+++ b/core/fpdfapi/page/cpdf_pageobjectholder_unittest.cpp
@@ -0,0 +1,66 @@
+// Copyright 2018 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/page/cpdf_pageobjectholder.h"
+
+#include <limits>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+// See https://crbug.com/852273
+TEST(CPDFPageObjectHolder, GraphicsDataAsKey) {
+  const float fMin = std::numeric_limits<float>::min();
+  const float fMax = std::numeric_limits<float>::max();
+  const float fInf = std::numeric_limits<float>::infinity();
+  const float fNan = std::numeric_limits<float>::quiet_NaN();
+
+  // Verify self-comparisions.
+  for (float c1 : {fMin, 1.0f, 2.0f, fMax, fInf, fNan}) {
+    for (float c2 : {fMin, 1.0f, 2.0f, fMax, fInf, fNan}) {
+      for (int c3 : {1, 2})
+        EXPECT_FALSE(GraphicsData({c1, c2, c3}) < GraphicsData({c1, c2, c3}));
+    }
+  }
+
+  std::map<GraphicsData, int> graphics_map;
+
+  // Insert in reverse index permuted order.
+  size_t x = 0;
+  for (int c3 : {2, 1}) {
+    for (float c2 : {fNan, fInf, fMax, 2.0f, 1.0f, fMin}) {
+      for (float c1 : {fNan, fInf, fMax, 2.0f, 1.0f, fMin}) {
+        graphics_map[{c1, c2, c3}] = x++;
+      }
+    }
+  }
+  EXPECT_EQ(72u, x);
+  EXPECT_EQ(72u, graphics_map.size());
+
+  // clang-format off
+  const int expected[72] = {
+      71, 35, 65, 29, 59, 23, 53, 17, 47, 11, 41, 5,
+      70, 34, 64, 28, 58, 22, 52, 16, 46, 10, 40, 4,
+      69, 33, 63, 27, 57, 21, 51, 15, 45, 9,  39, 3,
+      68, 32, 62, 26, 56, 20, 50, 14, 44, 8,  38, 2,
+      67, 31, 61, 25, 55, 19, 49, 13, 43, 7,  37, 1,
+      66, 30, 60, 24, 54, 18, 48, 12, 42, 6,  36, 0
+  };
+  // clang-format on
+
+  x = 0;
+  for (const auto& item : graphics_map) {
+    EXPECT_EQ(expected[x], item.second) << " for position " << x;
+    ++x;
+  }
+  EXPECT_EQ(72u, x);
+
+  // Erase in forward index permuted order.
+  for (int c3 : {1, 2}) {
+    for (float c2 : {fMin, 1.0f, 2.0f, fMax, fInf, fNan}) {
+      for (float c1 : {fMin, 1.0f, 2.0f, fMax, fInf, fNan})
+        graphics_map.erase({c1, c2, c3});
+    }
+  }
+  EXPECT_EQ(0u, graphics_map.size());
+}