Refactor CPDF_SimpleParser and add unit tests.

Remove unused member functions and simplify calls to find tag parameters.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1681403007 .

10 files changed, 149 insertions, 105 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 4f9f3757f1..de3570f6d1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1446,6 +1446,7 @@ test("pdfium_unittests") {
     "core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp",
     "core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp",
     "core/src/fpdfapi/fpdf_parser/fpdf_parser_parser_unittest.cpp",
+    "core/src/fpdfapi/fpdf_parser/fpdf_parser_utility_unittest.cpp",
     "core/src/fpdftext/fpdf_text_int_unittest.cpp",
     "core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp",
     "core/src/fxcrt/fx_basic_bstring_unittest.cpp",
diff --git a/core/include/fpdfapi/fpdf_parser.h b/core/include/fpdfapi/fpdf_parser.h
index 18a942e4e8..de32b1fb37 100644
--- a/core/include/fpdfapi/fpdf_parser.h
+++ b/core/include/fpdfapi/fpdf_parser.h
@@ -212,28 +212,16 @@ class CPDF_Document : public CFX_PrivateData, public CPDF_IndirectObjectHolder {
 class CPDF_SimpleParser {
  public:
   CPDF_SimpleParser(const uint8_t* pData, FX_DWORD dwSize);
-
   CPDF_SimpleParser(const CFX_ByteStringC& str);
 
   CFX_ByteStringC GetWord();
 
-  FX_BOOL SearchToken(const CFX_ByteStringC& token);
-
-  FX_BOOL SkipWord(const CFX_ByteStringC& token);
-
-  FX_BOOL FindTagPair(const CFX_ByteStringC& start_token,
-                      const CFX_ByteStringC& end_token,
-                      FX_DWORD& start_pos,
-                      FX_DWORD& end_pos);
+  // Find the token and its |nParams| parameters from the start of data,
+  // and move the current position to the start of those parameters.
+  bool FindTagParamFromStart(const CFX_ByteStringC& token, int nParams);
 
-  FX_BOOL FindTagParam(const CFX_ByteStringC& token, int nParams);
-
-  FX_DWORD GetPos() { return m_dwCurPos; }
-
-  void SetPos(FX_DWORD pos) {
-    ASSERT(pos <= m_dwSize);
-    m_dwCurPos = pos;
-  }
+  // For testing only.
+  FX_DWORD GetCurPos() const { return m_dwCurPos; }
 
  private:
   void ParseWord(const uint8_t*& pStart, FX_DWORD& dwSize);
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.cpp
index e6e2f2aabe..d1a7231d45 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.cpp
@@ -65,11 +65,13 @@ CPDF_SimpleParser::CPDF_SimpleParser(const uint8_t* pData, FX_DWORD dwSize) {
   m_dwSize = dwSize;
   m_dwCurPos = 0;
 }
+
 CPDF_SimpleParser::CPDF_SimpleParser(const CFX_ByteStringC& str) {
   m_pData = str.GetPtr();
   m_dwSize = str.GetLength();
   m_dwCurPos = 0;
 }
+
 void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, FX_DWORD& dwSize) {
   pStart = NULL;
   dwSize = 0;
@@ -146,6 +148,7 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, FX_DWORD& dwSize) {
     dwSize++;
   }
 }
+
 CFX_ByteStringC CPDF_SimpleParser::GetWord() {
   const uint8_t* pStart;
   FX_DWORD dwSize;
@@ -190,60 +193,14 @@ CFX_ByteStringC CPDF_SimpleParser::GetWord() {
   }
   return CFX_ByteStringC(pStart, dwSize);
 }
-FX_BOOL CPDF_SimpleParser::SearchToken(const CFX_ByteStringC& token) {
-  int token_len = token.GetLength();
-  while (m_dwCurPos < m_dwSize - token_len) {
-    if (FXSYS_memcmp(m_pData + m_dwCurPos, token.GetPtr(), token_len) == 0) {
-      break;
-    }
-    m_dwCurPos++;
-  }
-  if (m_dwCurPos == m_dwSize - token_len) {
-    return FALSE;
-  }
-  m_dwCurPos += token_len;
-  return TRUE;
-}
-FX_BOOL CPDF_SimpleParser::SkipWord(const CFX_ByteStringC& token) {
-  while (1) {
-    CFX_ByteStringC word = GetWord();
-    if (word.IsEmpty()) {
-      return FALSE;
-    }
-    if (word == token) {
-      return TRUE;
-    }
-  }
-  return FALSE;
-}
-FX_BOOL CPDF_SimpleParser::FindTagPair(const CFX_ByteStringC& start_token,
-                                       const CFX_ByteStringC& end_token,
-                                       FX_DWORD& start_pos,
-                                       FX_DWORD& end_pos) {
-  if (!start_token.IsEmpty()) {
-    if (!SkipWord(start_token)) {
-      return FALSE;
-    }
-    start_pos = m_dwCurPos;
-  }
-  while (1) {
-    end_pos = m_dwCurPos;
-    CFX_ByteStringC word = GetWord();
-    if (word.IsEmpty()) {
-      return FALSE;
-    }
-    if (word == end_token) {
-      return TRUE;
-    }
-  }
-  return FALSE;
-}
-FX_BOOL CPDF_SimpleParser::FindTagParam(const CFX_ByteStringC& token,
-                                        int nParams) {
+
+bool CPDF_SimpleParser::FindTagParamFromStart(const CFX_ByteStringC& token,
+                                              int nParams) {
   nParams++;
   FX_DWORD* pBuf = FX_Alloc(FX_DWORD, nParams);
   int buf_index = 0;
   int buf_count = 0;
+  m_dwCurPos = 0;
   while (1) {
     pBuf[buf_index++] = m_dwCurPos;
     if (buf_index == nParams) {
@@ -256,7 +213,7 @@ FX_BOOL CPDF_SimpleParser::FindTagParam(const CFX_ByteStringC& token,
     CFX_ByteStringC word = GetWord();
     if (word.IsEmpty()) {
       FX_Free(pBuf);
-      return FALSE;
+      return false;
     }
     if (word == token) {
       if (buf_count < nParams) {
@@ -264,10 +221,10 @@ FX_BOOL CPDF_SimpleParser::FindTagParam(const CFX_ByteStringC& token,
       }
       m_dwCurPos = pBuf[buf_index];
       FX_Free(pBuf);
-      return TRUE;
+      return true;
     }
   }
-  return FALSE;
+  return false;
 }
 
 CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
@@ -291,12 +248,14 @@ CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
   result.ReleaseBuffer((FX_STRSIZE)(pDest - pDestStart));
   return result;
 }
+
 CFX_ByteString PDF_NameDecode(const CFX_ByteString& orig) {
   if (!FXSYS_memchr(orig.c_str(), '#', orig.GetLength())) {
     return orig;
   }
   return PDF_NameDecode(CFX_ByteStringC(orig));
 }
+
 CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
   uint8_t* src_buf = (uint8_t*)orig.c_str();
   int src_len = orig.GetLength();
@@ -332,6 +291,7 @@ CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
   res.ReleaseBuffer();
   return res;
 }
+
 CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
   if (!pObj) {
     buf << " null";
@@ -402,6 +362,7 @@ CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
   }
   return buf;
 }
+
 FX_FLOAT PDF_ClipFloat(FX_FLOAT f) {
   if (f < 0) {
     return 0;
@@ -411,6 +372,7 @@ FX_FLOAT PDF_ClipFloat(FX_FLOAT f) {
   }
   return f;
 }
+
 static CPDF_Object* SearchNumberNode(CPDF_Dictionary* pNode, int num) {
   CPDF_Array* pLimits = pNode->GetArrayBy("Limits");
   if (pLimits &&
@@ -447,6 +409,7 @@ static CPDF_Object* SearchNumberNode(CPDF_Dictionary* pNode, int num) {
   }
   return NULL;
 }
+
 CPDF_Object* CPDF_NumberTree::LookupValue(int num) {
   return SearchNumberNode(m_pRoot, num);
 }
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility_unittest.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility_unittest.cpp
new file mode 100644
index 0000000000..1673798139
--- /dev/null
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_utility_unittest.cpp
@@ -0,0 +1,96 @@
+// Copyright 2016 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/include/fpdfapi/fpdf_parser.h"
+
+#include <string>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+TEST(SimpleParserTest, GetWord) {
+  pdfium::StrFuncTestData test_data[] = {
+      // Empty src string.
+      STR_TEST_CASE("", ""),
+      // Content with whitespaces only.
+      STR_TEST_CASE(" \t \0 \n", ""),
+      // Content with comments only.
+      STR_TEST_CASE("%this is a test case\r\n%2nd line", ""),
+      // Mixed whitespaces and comments.
+      STR_TEST_CASE(" \t \0%try()%haha\n %another line \aa", ""),
+      // Name.
+      STR_TEST_CASE(" /Tester ", "/Tester"),
+      // String.
+      STR_TEST_CASE("\t(nice day)!\n ", "(nice day)"),
+      // String with nested braces.
+      STR_TEST_CASE("\t(It is a (long) day)!\n ", "(It is a (long) day)"),
+      // String with escaped chars.
+      STR_TEST_CASE("\t(It is a \\(long\\) day!)hi\n ",
+                    "(It is a \\(long\\) day!)"),
+      // Hex string.
+      STR_TEST_CASE(" \n<4545acdfedertt>abc ", "<4545acdfedertt>"),
+      STR_TEST_CASE(" \n<4545a<ed>ertt>abc ", "<4545a<ed>"),
+      // Dictionary.
+      STR_TEST_CASE("<</oc 234 /color 2 3 R>>", "<<"),
+      STR_TEST_CASE("\t\t<< /abc>>", "<<"),
+      // Handling ending delimiters.
+      STR_TEST_CASE("> little bear", ">"),
+      STR_TEST_CASE(") another bear", ")"),
+      STR_TEST_CASE(">> end ", ">>"),
+      // No ending delimiters.
+      STR_TEST_CASE("(sdfgfgbcv", "(sdfgfgbcv"),
+      // Regular cases.
+      STR_TEST_CASE("apple pear", "apple"),
+      STR_TEST_CASE(" pi=3.1415 ", "pi=3.1415"),
+      STR_TEST_CASE(" p t x c ", "p"),
+      STR_TEST_CASE(" pt\0xc ", "pt"),
+      STR_TEST_CASE(" $^&&*\t\0sdff ", "$^&&*"),
+      STR_TEST_CASE("\n\r+3.5656 -11.0", "+3.5656"),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    const pdfium::StrFuncTestData& data = test_data[i];
+    CPDF_SimpleParser parser(data.input, data.input_size);
+    CFX_ByteStringC word = parser.GetWord();
+    EXPECT_EQ(std::string(reinterpret_cast<const char*>(data.expected),
+                          data.expected_size),
+              std::string(word.GetCStr(), word.GetLength()))
+        << " for case " << i;
+  }
+}
+
+TEST(SimpleParserTest, FindTagParamFromStart) {
+  struct FindTagTestStruct {
+    const unsigned char* input;
+    unsigned int input_size;
+    const char* token;
+    int num_params;
+    bool result;
+    unsigned int result_pos;
+  } test_data[] = {
+      // Empty strings.
+      STR_IN_TEST_CASE("", "Tj", 1, false, 0),
+      STR_IN_TEST_CASE("", "", 1, false, 0),
+      // Empty token.
+      STR_IN_TEST_CASE("  T j", "", 1, false, 5),
+      // No parameter.
+      STR_IN_TEST_CASE("Tj", "Tj", 1, false, 2),
+      STR_IN_TEST_CASE("(Tj", "Tj", 1, false, 3),
+      // Partial token match.
+      STR_IN_TEST_CASE("\r12\t34  56 78Tj", "Tj", 1, false, 15),
+      // Regular cases with various parameters.
+      STR_IN_TEST_CASE("\r\0abd Tj", "Tj", 1, true, 0),
+      STR_IN_TEST_CASE("12 4 Tj 3 46 Tj", "Tj", 1, true, 2),
+      STR_IN_TEST_CASE("er^ 2 (34) (5667) Tj", "Tj", 2, true, 5),
+      STR_IN_TEST_CASE("<344> (232)\t343.4\n12 45 Tj", "Tj", 3, true, 11),
+      STR_IN_TEST_CASE("1 2 3 4 5 6 7 8 cm", "cm", 6, true, 3),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    const FindTagTestStruct& data = test_data[i];
+    CPDF_SimpleParser parser(data.input, data.input_size);
+    EXPECT_EQ(data.result,
+              parser.FindTagParamFromStart(data.token, data.num_params))
+        << " for case " << i;
+    EXPECT_EQ(data.result_pos, parser.GetCurPos()) << " for case " << i;
+  }
+}
diff --git a/core/src/fpdfdoc/doc_ap.cpp b/core/src/fpdfdoc/doc_ap.cpp
index c84a36d499..b6134927cf 100644
--- a/core/src/fpdfdoc/doc_ap.cpp
+++ b/core/src/fpdfdoc/doc_ap.cpp
@@ -228,19 +228,16 @@ static CFX_ByteString GetFontSetString(IPVT_FontMap* pFontMap,
 }
 static CPVT_Color ParseColor(const CFX_ByteString& str) {
   CPDF_SimpleParser syntax(str);
-  syntax.SetPos(0);
-  if (syntax.FindTagParam("g", 1)) {
+  if (syntax.FindTagParamFromStart("g", 1)) {
     return CPVT_Color(CPVT_Color::kGray, FX_atof(syntax.GetWord()));
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam("rg", 3)) {
+  if (syntax.FindTagParamFromStart("rg", 3)) {
     FX_FLOAT f1 = FX_atof(syntax.GetWord());
     FX_FLOAT f2 = FX_atof(syntax.GetWord());
     FX_FLOAT f3 = FX_atof(syntax.GetWord());
     return CPVT_Color(CPVT_Color::kRGB, f1, f2, f3);
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam("k", 4)) {
+  if (syntax.FindTagParamFromStart("k", 4)) {
     FX_FLOAT f1 = FX_atof(syntax.GetWord());
     FX_FLOAT f2 = FX_atof(syntax.GetWord());
     FX_FLOAT f3 = FX_atof(syntax.GetWord());
@@ -288,7 +285,7 @@ static FX_BOOL GenerateWidgetAP(CPDF_Document* pDoc,
     return FALSE;
   }
   CPDF_SimpleParser syntax(DA);
-  syntax.FindTagParam("Tf", 2);
+  syntax.FindTagParamFromStart("Tf", 2);
   CFX_ByteString sFontName = syntax.GetWord();
   sFontName = PDF_NameDecode(sFontName);
   if (sFontName.IsEmpty()) {
diff --git a/core/src/fpdfdoc/doc_formfield.cpp b/core/src/fpdfdoc/doc_formfield.cpp
index 31557b490d..274459aec0 100644
--- a/core/src/fpdfdoc/doc_formfield.cpp
+++ b/core/src/fpdfdoc/doc_formfield.cpp
@@ -1075,7 +1075,7 @@ void CPDF_FormField::LoadDA() {
     return;
   }
   CPDF_SimpleParser syntax(DA);
-  syntax.FindTagParam("Tf", 2);
+  syntax.FindTagParamFromStart("Tf", 2);
   CFX_ByteString font_name = syntax.GetWord();
   CPDF_Dictionary* pFontDict = NULL;
   if (m_pForm->m_pFormDict && m_pForm->m_pFormDict->GetDictBy("DR") &&
diff --git a/core/src/fpdfdoc/doc_utils.cpp b/core/src/fpdfdoc/doc_utils.cpp
index a2c0454bc9..db905c880f 100644
--- a/core/src/fpdfdoc/doc_utils.cpp
+++ b/core/src/fpdfdoc/doc_utils.cpp
@@ -32,7 +32,7 @@ FX_BOOL CPDF_DefaultAppearance::HasFont() {
     return FALSE;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  return syntax.FindTagParam("Tf", 2);
+  return syntax.FindTagParamFromStart("Tf", 2);
 }
 CFX_ByteString CPDF_DefaultAppearance::GetFontString() {
   CFX_ByteString csFont;
@@ -40,7 +40,7 @@ CFX_ByteString CPDF_DefaultAppearance::GetFontString() {
     return csFont;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam("Tf", 2)) {
+  if (syntax.FindTagParamFromStart("Tf", 2)) {
     csFont += (CFX_ByteString)syntax.GetWord();
     csFont += " ";
     csFont += (CFX_ByteString)syntax.GetWord();
@@ -57,7 +57,7 @@ void CPDF_DefaultAppearance::GetFont(CFX_ByteString& csFontNameTag,
     return;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam("Tf", 2)) {
+  if (syntax.FindTagParamFromStart("Tf", 2)) {
     csFontNameTag = (CFX_ByteString)syntax.GetWord();
     csFontNameTag.Delete(0, 1);
     fFontSize = FX_atof((CFX_ByteString)syntax.GetWord());
@@ -69,15 +69,13 @@ FX_BOOL CPDF_DefaultAppearance::HasColor(FX_BOOL bStrokingOperation) {
     return FALSE;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam(bStrokingOperation ? "G" : "g", 1)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "G" : "g", 1)) {
     return TRUE;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "RG" : "rg", 3)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "RG" : "rg", 3)) {
     return TRUE;
   }
-  syntax.SetPos(0);
-  return syntax.FindTagParam(bStrokingOperation ? "K" : "k", 4);
+  return syntax.FindTagParamFromStart(bStrokingOperation ? "K" : "k", 4);
 }
 CFX_ByteString CPDF_DefaultAppearance::GetColorString(
     FX_BOOL bStrokingOperation) {
@@ -86,14 +84,13 @@ CFX_ByteString CPDF_DefaultAppearance::GetColorString(
     return csColor;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam(bStrokingOperation ? "G" : "g", 1)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "G" : "g", 1)) {
     csColor += (CFX_ByteString)syntax.GetWord();
     csColor += " ";
     csColor += (CFX_ByteString)syntax.GetWord();
     return csColor;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "RG" : "rg", 3)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "RG" : "rg", 3)) {
     csColor += (CFX_ByteString)syntax.GetWord();
     csColor += " ";
     csColor += (CFX_ByteString)syntax.GetWord();
@@ -103,8 +100,7 @@ CFX_ByteString CPDF_DefaultAppearance::GetColorString(
     csColor += (CFX_ByteString)syntax.GetWord();
     return csColor;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "K" : "k", 4)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "K" : "k", 4)) {
     csColor += (CFX_ByteString)syntax.GetWord();
     csColor += " ";
     csColor += (CFX_ByteString)syntax.GetWord();
@@ -128,21 +124,19 @@ void CPDF_DefaultAppearance::GetColor(int& iColorType,
     return;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam(bStrokingOperation ? "G" : "g", 1)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "G" : "g", 1)) {
     iColorType = COLORTYPE_GRAY;
     fc[0] = FX_atof((CFX_ByteString)syntax.GetWord());
     return;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "RG" : "rg", 3)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "RG" : "rg", 3)) {
     iColorType = COLORTYPE_RGB;
     fc[0] = FX_atof((CFX_ByteString)syntax.GetWord());
     fc[1] = FX_atof((CFX_ByteString)syntax.GetWord());
     fc[2] = FX_atof((CFX_ByteString)syntax.GetWord());
     return;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "K" : "k", 4)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "K" : "k", 4)) {
     iColorType = COLORTYPE_CMYK;
     fc[0] = FX_atof((CFX_ByteString)syntax.GetWord());
     fc[1] = FX_atof((CFX_ByteString)syntax.GetWord());
@@ -159,14 +153,13 @@ void CPDF_DefaultAppearance::GetColor(FX_ARGB& color,
     return;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam(bStrokingOperation ? "G" : "g", 1)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "G" : "g", 1)) {
     iColorType = COLORTYPE_GRAY;
     FX_FLOAT g = FX_atof((CFX_ByteString)syntax.GetWord()) * 255 + 0.5f;
     color = ArgbEncode(255, (int)g, (int)g, (int)g);
     return;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "RG" : "rg", 3)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "RG" : "rg", 3)) {
     iColorType = COLORTYPE_RGB;
     FX_FLOAT r = FX_atof((CFX_ByteString)syntax.GetWord()) * 255 + 0.5f;
     FX_FLOAT g = FX_atof((CFX_ByteString)syntax.GetWord()) * 255 + 0.5f;
@@ -174,8 +167,7 @@ void CPDF_DefaultAppearance::GetColor(FX_ARGB& color,
     color = ArgbEncode(255, (int)r, (int)g, (int)b);
     return;
   }
-  syntax.SetPos(0);
-  if (syntax.FindTagParam(bStrokingOperation ? "K" : "k", 4)) {
+  if (syntax.FindTagParamFromStart(bStrokingOperation ? "K" : "k", 4)) {
     iColorType = COLORTYPE_CMYK;
     FX_FLOAT c = FX_atof((CFX_ByteString)syntax.GetWord());
     FX_FLOAT m = FX_atof((CFX_ByteString)syntax.GetWord());
@@ -193,7 +185,7 @@ FX_BOOL CPDF_DefaultAppearance::HasTextMatrix() {
     return FALSE;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  return syntax.FindTagParam("Tm", 6);
+  return syntax.FindTagParamFromStart("Tm", 6);
 }
 CFX_ByteString CPDF_DefaultAppearance::GetTextMatrixString() {
   CFX_ByteString csTM;
@@ -201,7 +193,7 @@ CFX_ByteString CPDF_DefaultAppearance::GetTextMatrixString() {
     return csTM;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam("Tm", 6)) {
+  if (syntax.FindTagParamFromStart("Tm", 6)) {
     for (int i = 0; i < 6; i++) {
       csTM += (CFX_ByteString)syntax.GetWord();
       csTM += " ";
@@ -216,7 +208,7 @@ CFX_Matrix CPDF_DefaultAppearance::GetTextMatrix() {
     return tm;
   }
   CPDF_SimpleParser syntax(m_csDA);
-  if (syntax.FindTagParam("Tm", 6)) {
+  if (syntax.FindTagParamFromStart("Tm", 6)) {
     FX_FLOAT f[6];
     for (int i = 0; i < 6; i++) {
       f[i] = FX_atof((CFX_ByteString)syntax.GetWord());
diff --git a/fpdfsdk/src/formfiller/FFL_CBA_Fontmap.cpp b/fpdfsdk/src/formfiller/FFL_CBA_Fontmap.cpp
index 7f5fd9430d..96f727eee6 100644
--- a/fpdfsdk/src/formfiller/FFL_CBA_Fontmap.cpp
+++ b/fpdfsdk/src/formfiller/FFL_CBA_Fontmap.cpp
@@ -233,7 +233,7 @@ CPDF_Font* CBA_FontMap::GetAnnotDefaultFont(CFX_ByteString& sAlias) {
 
   if (!sDA.IsEmpty()) {
     CPDF_SimpleParser syntax(sDA);
-    syntax.FindTagParam("Tf", 2);
+    syntax.FindTagParamFromStart("Tf", 2);
     CFX_ByteString sFontName = syntax.GetWord();
     sAlias = PDF_NameDecode(sFontName).Mid(1);
 
diff --git a/pdfium.gyp b/pdfium.gyp
index 0c40eff791..ffebc4f52d 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -754,6 +754,7 @@
         'core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_unittest.cpp',
         'core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp',
         'core/src/fpdfapi/fpdf_parser/fpdf_parser_parser_unittest.cpp',
+        'core/src/fpdfapi/fpdf_parser/fpdf_parser_utility_unittest.cpp',
         'core/src/fpdftext/fpdf_text_int_unittest.cpp',
         'core/src/fxcodec/codec/fx_codec_jpx_unittest.cpp',
         'core/src/fxcrt/fx_basic_bstring_unittest.cpp',
diff --git a/testing/test_support.h b/testing/test_support.h
index ec896fdc85..16ed06f8df 100644
--- a/testing/test_support.h
+++ b/testing/test_support.h
@@ -18,6 +18,12 @@
 
 namespace pdfium {
 
+#define STR_IN_TEST_CASE(input_literal, ...)                         \
+  {                                                                  \
+    (const unsigned char*) input_literal, sizeof(input_literal) - 1, \
+        __VA_ARGS__                                                  \
+  }
+
 #define STR_IN_OUT_CASE(input_literal, expected_literal, ...)                 \
   {                                                                           \
     (const unsigned char*) input_literal, sizeof(input_literal) - 1,          \