Add test for CPDF_StreamParser::ReadHexString.

core/src/fpdfapi/fpdf_page/fpdf_page_parser_old_unittest.cpp

+// Copyright 2015 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 "testing/gtest/include/gtest/gtest.h"
+
+#include "pageint.h"
+
+TEST(fpdf_page_parser_old, ReadHexString) {
+  {
+    // Position out of bounds.
+    uint8_t data[] = "12ab>";
+    CPDF_StreamParser parser(data, 5);
+    parser.SetPos(6);
+    EXPECT_EQ("", parser.ReadHexString());
+  }
+
+  {
+    // Regular conversion.
+    uint8_t data[] = "1A2b>abcd";
+    CPDF_StreamParser parser(data, 5);
+    EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
+    EXPECT_EQ(5, parser.GetPos());
+  }
+
+  {
+    // Missing ending >
+    uint8_t data[] = "1A2b";
+    CPDF_StreamParser parser(data, 5);
+    EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
+    EXPECT_EQ(5, parser.GetPos());
+  }
+
+  {
+    // Uneven number of bytes.
+    uint8_t data[] = "1A2>asdf";
+    CPDF_StreamParser parser(data, 5);
+    EXPECT_EQ("\x1a\x20", parser.ReadHexString());
+    EXPECT_EQ(4, parser.GetPos());
+  }
+
+  {
+    uint8_t data[] = ">";
+    CPDF_StreamParser parser(data, 5);
+    EXPECT_EQ("", parser.ReadHexString());
+    EXPECT_EQ(1, parser.GetPos());
+  }
+}