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>

7 files changed, 35 insertions, 34 deletions

diff --git a/xfa/fxfa/parser/cxfa_dataexporter.cpp b/xfa/fxfa/parser/cxfa_dataexporter.cpp
index 49a1f5857b..ff9e981e9f 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.cpp
+++ b/xfa/fxfa/parser/cxfa_dataexporter.cpp
@@ -225,10 +225,10 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
           break;
 
         std::vector<CFX_WideString> wsSelTextArray;
-        int32_t iStart = 0;
-        int32_t iEnd = wsRawValue.Find(L'\n', iStart);
-        iEnd = (iEnd == -1) ? wsRawValue.GetLength() : iEnd;
-        while (iEnd >= iStart) {
+        FX_STRSIZE iStart = 0;
+        FX_STRSIZE iEnd = wsRawValue.Find(L'\n', iStart);
+        iEnd = (iEnd == FX_STRNPOS) ? wsRawValue.GetLength() : iEnd;
+        while (iEnd != FX_STRNPOS && iEnd >= iStart) {
           wsSelTextArray.push_back(wsRawValue.Mid(iStart, iEnd - iStart));
           iStart = iEnd + 1;
           if (iStart >= wsRawValue.GetLength())
diff --git a/xfa/fxfa/parser/cxfa_document.cpp b/xfa/fxfa/parser/cxfa_document.cpp
index 16b999b9e3..f43deaf145 100644
--- a/xfa/fxfa/parser/cxfa_document.cpp
+++ b/xfa/fxfa/parser/cxfa_document.cpp
@@ -306,7 +306,7 @@ XFA_VERSION CXFA_Document::RecognizeXFAVersionNumber(
     return XFA_VERSION_UNKNOWN;
   }
   FX_STRSIZE nDotPos = wsTemplateNS.Find('.', nPrefixLength);
-  if (nDotPos == (FX_STRSIZE)-1)
+  if (nDotPos == FX_STRNPOS)
     return XFA_VERSION_UNKNOWN;
 
   int8_t iMajor = FXSYS_wtoi(
@@ -368,7 +368,7 @@ void CXFA_Document::DoProtoMerge() {
     if (pUseHrefNode->TryCData(XFA_ATTRIBUTE_Usehref, wsUseVal) &&
         !wsUseVal.IsEmpty()) {
       FX_STRSIZE uSharpPos = wsUseVal.Find('#');
-      if (uSharpPos < 0) {
+      if (uSharpPos == FX_STRNPOS) {
         wsURI = wsUseVal.AsStringC();
       } else {
         wsURI = CFX_WideStringC(wsUseVal.c_str(), uSharpPos);
diff --git a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
index 4d6886d7e1..55851bb34a 100644
--- a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
@@ -148,9 +148,10 @@ CXFA_Node* ResolveBreakTarget(CXFA_Node* pPageSetRoot,
   bool bTargetAllFind = true;
   while (iSplitIndex != -1) {
     CFX_WideString wsExpr;
-    int32_t iSplitNextIndex = 0;
+    FX_STRSIZE iSplitNextIndex = 0;
     if (!bTargetAllFind) {
       iSplitNextIndex = wsTargetAll.Find(' ', iSplitIndex);
+      ASSERT(iSplitNextIndex != FX_STRNPOS);
       wsExpr = wsTargetAll.Mid(iSplitIndex, iSplitNextIndex - iSplitIndex);
     } else {
       wsExpr = wsTargetAll;
diff --git a/xfa/fxfa/parser/cxfa_localevalue.cpp b/xfa/fxfa/parser/cxfa_localevalue.cpp
index 5b5c27f1d4..aa0f74b170 100644
--- a/xfa/fxfa/parser/cxfa_localevalue.cpp
+++ b/xfa/fxfa/parser/cxfa_localevalue.cpp
@@ -49,10 +49,10 @@ bool ValueSplitDateTime(const CFX_WideString& wsDateTime,
   if (wsDateTime.IsEmpty())
     return false;
 
-  int nSplitIndex = wsDateTime.Find('T');
-  if (nSplitIndex < 0)
+  FX_STRSIZE nSplitIndex = wsDateTime.Find('T');
+  if (nSplitIndex == FX_STRNPOS)
     nSplitIndex = wsDateTime.Find(' ');
-  if (nSplitIndex < 0)
+  if (nSplitIndex == FX_STRNPOS)
     return false;
 
   wsDate = wsDateTime.Left(nSplitIndex);
@@ -444,7 +444,7 @@ bool CXFA_LocaleValue::ValidateCanonicalDate(const CFX_WideString& wsDate,
   if (nLen < wCountY || nLen > wCountY + wCountM + wCountD + 2)
     return false;
 
-  const bool bSymbol = wsDate.Find(0x2D) != -1;
+  const bool bSymbol = wsDate.Find(0x2D) != FX_STRNPOS;
   uint16_t wYear = 0;
   uint16_t wMonth = 0;
   uint16_t wDay = 0;
@@ -519,7 +519,7 @@ bool CXFA_LocaleValue::ValidateCanonicalTime(const CFX_WideString& wsTime) {
   const uint16_t wCountM = 2;
   const uint16_t wCountS = 2;
   const uint16_t wCountF = 3;
-  const bool bSymbol = wsTime.Find(':') != -1;
+  const bool bSymbol = wsTime.Find(':') != FX_STRNPOS;
   uint16_t wHour = 0;
   uint16_t wMinute = 0;
   uint16_t wSecond = 0;
@@ -558,7 +558,8 @@ bool CXFA_LocaleValue::ValidateCanonicalTime(const CFX_WideString& wsTime) {
     wSecond = pTime[nIndex] - '0' + wSecond * 10;
     nIndex++;
   }
-  if (wsTime.Find('.') > 0) {
+  FX_STRSIZE ret = wsTime.Find('.');
+  if (ret && ret != FX_STRNPOS) {
     if (pTime[nIndex] != '.')
       return false;
     nIndex++;
diff --git a/xfa/fxfa/parser/cxfa_node.cpp b/xfa/fxfa/parser/cxfa_node.cpp
index 261fee1971..8497e60a74 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -4043,10 +4043,10 @@ bool CXFA_Node::SetScriptContent(const CFX_WideString& wsContent,
           std::vector<CFX_WideString> wsSaveTextArray;
           size_t iSize = 0;
           if (!wsContent.IsEmpty()) {
-            int32_t iStart = 0;
-            int32_t iLength = wsContent.GetLength();
-            int32_t iEnd = wsContent.Find(L'\n', iStart);
-            iEnd = (iEnd == -1) ? iLength : iEnd;
+            FX_STRSIZE iStart = 0;
+            FX_STRSIZE iLength = wsContent.GetLength();
+            FX_STRSIZE iEnd = wsContent.Find(L'\n', iStart);
+            iEnd = (iEnd == FX_STRNPOS) ? iLength : iEnd;
             while (iEnd >= iStart) {
               wsSaveTextArray.push_back(wsContent.Mid(iStart, iEnd - iStart));
               iStart = iEnd + 1;
@@ -4054,7 +4054,7 @@ bool CXFA_Node::SetScriptContent(const CFX_WideString& wsContent,
                 break;
               }
               iEnd = wsContent.Find(L'\n', iStart);
-              if (iEnd < 0) {
+              if (iEnd == FX_STRNPOS) {
                 wsSaveTextArray.push_back(
                     wsContent.Mid(iStart, iLength - iStart));
               }
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.cpp b/xfa/fxfa/parser/cxfa_simple_parser.cpp
index 1b5cccf101..39dc858b9e 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_simple_parser.cpp
@@ -93,7 +93,7 @@ bool GetAttributeLocalName(const CFX_WideStringC& wsAttributeName,
                            CFX_WideString& wsLocalAttrName) {
   CFX_WideString wsAttrName(wsAttributeName);
   FX_STRSIZE iFind = wsAttrName.Find(L':', 0);
-  if (iFind < 0) {
+  if (iFind == FX_STRNPOS) {
     wsLocalAttrName = wsAttrName;
     return false;
   }
@@ -135,7 +135,7 @@ bool FindAttributeWithNS(CFX_XMLElement* pElement,
   for (auto it : pElement->GetAttributes()) {
     FX_STRSIZE iFind = it.first.Find(L':', 0);
     CFX_WideString wsNSPrefix;
-    if (iFind < 0) {
+    if (iFind == FX_STRNPOS) {
       if (wsLocalAttributeName != it.first)
         continue;
     } else {
diff --git a/xfa/fxfa/parser/cxfa_widgetdata.cpp b/xfa/fxfa/parser/cxfa_widgetdata.cpp
index 5efc0ea481..34e3aeaf0f 100644
--- a/xfa/fxfa/parser/cxfa_widgetdata.cpp
+++ b/xfa/fxfa/parser/cxfa_widgetdata.cpp
@@ -42,11 +42,10 @@ bool SplitDateTime(const CFX_WideString& wsDateTime,
   if (wsDateTime.IsEmpty())
     return false;
 
-  int nSplitIndex = -1;
-  nSplitIndex = wsDateTime.Find('T');
-  if (nSplitIndex < 0)
+  FX_STRSIZE nSplitIndex = wsDateTime.Find('T');
+  if (nSplitIndex == FX_STRNPOS)
     nSplitIndex = wsDateTime.Find(' ');
-  if (nSplitIndex < 0)
+  if (nSplitIndex == FX_STRNPOS)
     return false;
 
   wsDate = wsDateTime.Left(nSplitIndex);
@@ -848,17 +847,17 @@ std::vector<CFX_WideString> CXFA_WidgetData::GetSelectedItemsValue() {
   CFX_WideString wsValue = GetRawValue();
   if (GetChoiceListOpen() == XFA_ATTRIBUTEENUM_MultiSelect) {
     if (!wsValue.IsEmpty()) {
-      int32_t iStart = 0;
-      int32_t iLength = wsValue.GetLength();
-      int32_t iEnd = wsValue.Find(L'\n', iStart);
-      iEnd = (iEnd == -1) ? iLength : iEnd;
+      FX_STRSIZE iStart = 0;
+      FX_STRSIZE iLength = wsValue.GetLength();
+      FX_STRSIZE iEnd = wsValue.Find(L'\n', iStart);
+      iEnd = (iEnd == FX_STRNPOS) ? iLength : iEnd;
       while (iEnd >= iStart) {
         wsSelTextArray.push_back(wsValue.Mid(iStart, iEnd - iStart));
         iStart = iEnd + 1;
         if (iStart >= iLength)
           break;
         iEnd = wsValue.Find(L'\n', iStart);
-        if (iEnd < 0)
+        if (iEnd == FX_STRNPOS)
           wsSelTextArray.push_back(wsValue.Mid(iStart, iLength - iStart));
       }
     }
@@ -1318,7 +1317,7 @@ bool CXFA_WidgetData::GetBarcodeAttribute_WideNarrowRatio(float* val) {
   if (pUIChild->TryCData(XFA_ATTRIBUTE_WideNarrowRatio, wsWideNarrowRatio)) {
     FX_STRSIZE ptPos = wsWideNarrowRatio.Find(':');
     float fRatio = 0;
-    if (ptPos >= 0) {
+    if (ptPos != FX_STRNPOS) {
       fRatio = (float)FXSYS_wtoi(wsWideNarrowRatio.c_str());
     } else {
       int32_t fA, fB;
@@ -1743,9 +1742,9 @@ void CXFA_WidgetData::NormalizeNumStr(const CFX_WideString& wsValue,
 
   wsOutput = wsValue;
   wsOutput.TrimLeft('0');
-  int32_t dot_index = wsOutput.Find('.');
+  FX_STRSIZE dot_index = wsOutput.Find('.');
   int32_t iFracDigits = 0;
-  if (!wsOutput.IsEmpty() && dot_index >= 0 &&
+  if (!wsOutput.IsEmpty() && dot_index != FX_STRNPOS &&
       (!GetFracDigits(iFracDigits) || iFracDigits != -1)) {
     wsOutput.TrimRight(L"0");
     wsOutput.TrimRight(L".");
@@ -1769,8 +1768,8 @@ void CXFA_WidgetData::FormatNumStr(const CFX_WideString& wsValue,
     wsSrcNum.Delete(0, 1);
   }
   int32_t len = wsSrcNum.GetLength();
-  int32_t dot_index = wsSrcNum.Find('.');
-  if (dot_index == -1)
+  FX_STRSIZE dot_index = wsSrcNum.Find('.');
+  if (dot_index == FX_STRNPOS)
     dot_index = len;
 
   int32_t cc = dot_index - 1;