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>

1 files changed, 5 insertions, 4 deletions

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);