Replace raw value for constant error value in string operations

Currently Find() and other methods that return a FX_STRSIZE return -1
to indicate error/failure. This means that there is a lot of magic
numbers and magic checks floating around. The standard library for
similar operations uses a npos constant. This CL implements
FX_STRNPOS, and replaces usages of magic number checking. It also does
some type cleanup along the way where it was obvious that FX_STRSIZE
should be being used.

Removing the magic numbers should make eventually changing FX_STRSIZE
to be unsigned easier in the future.

BUG=pdfium:828

Change-Id: I67e481e44cf2f75a1698afa8fbee4f375a74c490
Reviewed-on: https://pdfium-review.googlesource.com/9651
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

4 files changed, 23 insertions, 22 deletions

diff --git a/fpdfsdk/fpdfedittext.cpp b/fpdfsdk/fpdfedittext.cpp
index 02bf722462..f498917a19 100644
--- a/fpdfsdk/fpdfedittext.cpp
+++ b/fpdfsdk/fpdfedittext.cpp
@@ -39,7 +39,7 @@ CPDF_Dictionary* LoadFontDesc(CPDF_Document* pDoc,
   int flags = 0;
   if (FXFT_Is_Face_fixedwidth(pFont->GetFace()))
     flags |= FXFONT_FIXED_PITCH;
-  if (font_name.Find("Serif") > -1)
+  if (font_name.Find("Serif") != FX_STRNPOS)
     flags |= FXFONT_SERIF;
   if (FXFT_Is_Face_Italic(pFont->GetFace()))
     flags |= FXFONT_ITALIC;
diff --git a/fpdfsdk/fpdfppo.cpp b/fpdfsdk/fpdfppo.cpp
index beab7d87d3..bf52932a1d 100644
--- a/fpdfsdk/fpdfppo.cpp
+++ b/fpdfsdk/fpdfppo.cpp
@@ -80,20 +80,20 @@ bool ParserPageRangeString(CFX_ByteString rangstring,
   int nLength = rangstring.GetLength();
   CFX_ByteString cbCompareString("0123456789-,");
   for (int i = 0; i < nLength; ++i) {
-    if (cbCompareString.Find(rangstring[i]) == -1)
+    if (cbCompareString.Find(rangstring[i]) == FX_STRNPOS)
       return false;
   }
 
   CFX_ByteString cbMidRange;
-  int nStringFrom = 0;
-  int nStringTo = 0;
+  FX_STRSIZE nStringFrom = 0;
+  FX_STRSIZE nStringTo = 0;
   while (nStringTo < nLength) {
     nStringTo = rangstring.Find(',', nStringFrom);
-    if (nStringTo == -1)
+    if (nStringTo == FX_STRNPOS)
       nStringTo = nLength;
     cbMidRange = rangstring.Mid(nStringFrom, nStringTo - nStringFrom);
-    int nMid = cbMidRange.Find('-');
-    if (nMid == -1) {
+    FX_STRSIZE nMid = cbMidRange.Find('-');
+    if (nMid == FX_STRNPOS) {
       long lPageNum = atol(cbMidRange.c_str());
       if (lPageNum <= 0 || lPageNum > nCount)
         return false;
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
index 052bed55d2..7cccd2fb11 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
@@ -809,19 +809,19 @@ bool CPDFXFA_DocEnvironment::ExportSubmitFile(FPDF_FILEHANDLER* pFileHandler,
 
 void CPDFXFA_DocEnvironment::ToXFAContentFlags(CFX_WideString csSrcContent,
                                                FPDF_DWORD& flag) {
-  if (csSrcContent.Find(L" config ", 0) != -1)
+  if (csSrcContent.Find(L" config ", 0) != FX_STRNPOS)
     flag |= FXFA_CONFIG;
-  if (csSrcContent.Find(L" template ", 0) != -1)
+  if (csSrcContent.Find(L" template ", 0) != FX_STRNPOS)
     flag |= FXFA_TEMPLATE;
-  if (csSrcContent.Find(L" localeSet ", 0) != -1)
+  if (csSrcContent.Find(L" localeSet ", 0) != FX_STRNPOS)
     flag |= FXFA_LOCALESET;
-  if (csSrcContent.Find(L" datasets ", 0) != -1)
+  if (csSrcContent.Find(L" datasets ", 0) != FX_STRNPOS)
     flag |= FXFA_DATASETS;
-  if (csSrcContent.Find(L" xmpmeta ", 0) != -1)
+  if (csSrcContent.Find(L" xmpmeta ", 0) != FX_STRNPOS)
     flag |= FXFA_XMPMETA;
-  if (csSrcContent.Find(L" xfdf ", 0) != -1)
+  if (csSrcContent.Find(L" xfdf ", 0) != FX_STRNPOS)
     flag |= FXFA_XFDF;
-  if (csSrcContent.Find(L" form ", 0) != -1)
+  if (csSrcContent.Find(L" form ", 0) != FX_STRNPOS)
     flag |= FXFA_FORM;
   if (flag == 0) {
     flag = FXFA_CONFIG | FXFA_TEMPLATE | FXFA_LOCALESET | FXFA_DATASETS |
@@ -840,11 +840,11 @@ bool CPDFXFA_DocEnvironment::MailToInfo(CFX_WideString& csURL,
   if (srcURL.Left(7).CompareNoCase(L"mailto:") != 0)
     return false;
 
-  int pos = srcURL.Find(L'?', 0);
+  FX_STRSIZE pos = srcURL.Find(L'?', 0);
   CFX_WideString tmp;
-  if (pos == -1) {
+  if (pos == FX_STRNPOS) {
     pos = srcURL.Find(L'@', 0);
-    if (pos == -1)
+    if (pos == FX_STRNPOS)
       return false;
 
     tmp = srcURL.Right(csURL.GetLength() - 7);
@@ -863,7 +863,7 @@ bool CPDFXFA_DocEnvironment::MailToInfo(CFX_WideString& csURL,
     srcURL.TrimRight();
     pos = srcURL.Find(L'&', 0);
 
-    tmp = (pos == -1) ? srcURL : srcURL.Left(pos);
+    tmp = (pos == FX_STRNPOS) ? srcURL : srcURL.Left(pos);
     tmp.TrimLeft();
     tmp.TrimRight();
     if (tmp.GetLength() >= 3 && tmp.Left(3).CompareNoCase(L"cc=") == 0) {
diff --git a/fpdfsdk/javascript/PublicMethods.cpp b/fpdfsdk/javascript/PublicMethods.cpp
index 06ed64c7cc..f5d3c68780 100644
--- a/fpdfsdk/javascript/PublicMethods.cpp
+++ b/fpdfsdk/javascript/PublicMethods.cpp
@@ -526,7 +526,7 @@ double CJS_PublicMethods::MakeRegularDate(const CFX_WideString& value,
                 CFX_WideString sFullMonths = fullmonths[m];
                 sFullMonths.MakeLower();
 
-                if (sFullMonths.Find(sMonth.c_str(), 0) != -1) {
+                if (sFullMonths.Find(sMonth.c_str(), 0) != FX_STRNPOS) {
                   nMonth = m + 1;
                   i += 4;
                   j += nSkip;
@@ -932,7 +932,8 @@ bool CJS_PublicMethods::AFNumber_Keystroke(CJS_Runtime* pRuntime,
                                  pEvent->SelEnd() - pEvent->SelStart());
   }
 
-  bool bHasSign = wstrValue.Find(L'-') != -1 && wstrSelected.Find(L'-') == -1;
+  bool bHasSign = wstrValue.Find(L'-') != FX_STRNPOS &&
+                  wstrSelected.Find(L'-') == FX_STRNPOS;
   if (bHasSign) {
     // can't insert "change" in front to sign postion.
     if (pEvent->SelStart() == 0) {
@@ -946,7 +947,7 @@ bool CJS_PublicMethods::AFNumber_Keystroke(CJS_Runtime* pRuntime,
     iSepStyle = 0;
   const wchar_t cSep = iSepStyle < 2 ? L'.' : L',';
 
-  bool bHasSep = wstrValue.Find(cSep) != -1;
+  bool bHasSep = wstrValue.Find(cSep) != FX_STRNPOS;
   for (FX_STRSIZE i = 0; i < wstrChange.GetLength(); ++i) {
     if (wstrChange[i] == cSep) {
       if (bHasSep) {
@@ -1111,7 +1112,7 @@ bool CJS_PublicMethods::AFDate_FormatEx(CJS_Runtime* pRuntime,
   CFX_WideString sFormat = params[0].ToCFXWideString(pRuntime);
   double dDate = 0.0f;
 
-  if (strValue.Find(L"GMT") != -1) {
+  if (strValue.Find(L"GMT") != FX_STRNPOS) {
     // for GMT format time
     // such as "Tue Aug 11 14:24:16 GMT+08002009"
     dDate = MakeInterDate(strValue);