Convert FX_STRSIZE int->size_t

Change the underlying type for FX_STRSIZE to size_t from int. This
will make the value unsigned and thus all values in the range of the
type will be valid. This allows for the final remove of negative
length strings, but also introduces a some casting and functional 
errors, since many parts of the code base assume that FX_STRSIZE is 
int or another signed type. This also CL fixes these errors.

BUG=pdfium:828

Change-Id: I231dca59e96fc9330cbb099eecbdfc41fcf86f5b
Reviewed-on: https://pdfium-review.googlesource.com/11830
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

3 files changed, 21 insertions, 11 deletions

diff --git a/xfa/fgas/crt/cfgas_formatstring.cpp b/xfa/fgas/crt/cfgas_formatstring.cpp
index 9da8bb9583..df95a3588a 100644
--- a/xfa/fgas/crt/cfgas_formatstring.cpp
+++ b/xfa/fgas/crt/cfgas_formatstring.cpp
@@ -293,7 +293,7 @@ bool ParseLocaleDate(const CFX_WideString& wsDate,
         }
       }
     } else if (symbol == L"YY" || symbol == L"YYYY") {
-      if (*cc + symbol.GetLength() > len)
+      if (*cc + pdfium::base::checked_cast<int32_t>(symbol.GetLength()) > len)
         return false;
 
       year = 0;
@@ -417,11 +417,13 @@ bool ParseLocaleTime(const CFX_WideString& wsTime,
     } else if (symbol == L"A") {
       CFX_WideString wsAM = pLocale->GetMeridiemName(true);
       CFX_WideString wsPM = pLocale->GetMeridiemName(false);
-      if ((*cc + wsAM.GetLength() <= len) &&
+      if ((*cc + pdfium::base::checked_cast<int32_t>(wsAM.GetLength()) <=
+           len) &&
           (CFX_WideStringC(str + *cc, wsAM.GetLength()) == wsAM)) {
         *cc += wsAM.GetLength();
         bHasA = true;
-      } else if ((*cc + wsPM.GetLength() <= len) &&
+      } else if ((*cc + pdfium::base::checked_cast<int32_t>(wsPM.GetLength()) <=
+                  len) &&
                  (CFX_WideStringC(str + *cc, wsPM.GetLength()) == wsPM)) {
         *cc += wsPM.GetLength();
         bHasA = true;
@@ -2087,12 +2089,13 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
   if (cc >= 0) {
     int nPos = dot_index.value() % 3;
     wsOutput->clear();
-    for (int32_t i = 0; i < dot_index; i++) {
+    for (int32_t i = 0;
+         i < pdfium::base::checked_cast<int32_t>(dot_index.value()); i++) {
       if (i % 3 == nPos && i != 0)
         *wsOutput += wsGroupSymbol;
       *wsOutput += wsSrcNum[i];
     }
-    if (dot_index < len) {
+    if (pdfium::base::checked_cast<int32_t>(dot_index.value()) < len) {
       *wsOutput += pLocale->GetNumbericSymbol(FX_LOCALENUMSYMBOL_Decimal);
       *wsOutput += wsSrcNum.Right(len - dot_index.value() - 1);
     }
@@ -2102,7 +2105,8 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
     }
     return false;
   }
-  if (dot_index_f == wsNumFormat.GetLength()) {
+  if (dot_index_f ==
+      pdfium::base::checked_cast<int32_t>(wsNumFormat.GetLength())) {
     if (!bAddNeg && bNeg) {
       *wsOutput =
           pLocale->GetNumbericSymbol(FX_LOCALENUMSYMBOL_Minus) + *wsOutput;
@@ -2115,7 +2119,7 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
   if (strf[dot_index_f] == 'V') {
     *wsOutput += wsDotSymbol;
   } else if (strf[dot_index_f] == '.') {
-    if (dot_index < len)
+    if (pdfium::base::checked_cast<int32_t>(dot_index.value()) < len)
       *wsOutput += wsDotSymbol;
     else if (strf[dot_index_f + 1] == '9' || strf[dot_index_f + 1] == 'Z')
       *wsOutput += wsDotSymbol;
diff --git a/xfa/fxfa/fm2js/cxfa_fmsimpleexpression_unittest.cpp b/xfa/fxfa/fm2js/cxfa_fmsimpleexpression_unittest.cpp
index c465c96ff0..58ddbac806 100644
--- a/xfa/fxfa/fm2js/cxfa_fmsimpleexpression_unittest.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmsimpleexpression_unittest.cpp
@@ -66,7 +66,7 @@ TEST(FMStringExpressionTest, Long) {
   CFX_WideTextBuf accumulator;
   std::vector<CFX_WideStringC::UnsignedType> vec(140000, L'A');
   CXFA_FMStringExpression(1, CFX_WideStringC(vec)).ToJavaScript(accumulator);
-  EXPECT_EQ(140000, accumulator.GetLength());
+  EXPECT_EQ(140000u, accumulator.GetLength());
 }
 
 TEST(FMStringExpressionTest, Quoted) {
diff --git a/xfa/fxfa/parser/cxfa_scriptcontext.cpp b/xfa/fxfa/parser/cxfa_scriptcontext.cpp
index e7c86296ee..98b5da057f 100644
--- a/xfa/fxfa/parser/cxfa_scriptcontext.cpp
+++ b/xfa/fxfa/parser/cxfa_scriptcontext.cpp
@@ -624,7 +624,9 @@ int32_t CXFA_ScriptContext::ResolveObjects(CXFA_Object* refObject,
       bool bCreate =
           m_ResolveProcessor->GetNodeHelper()->ResolveNodes_CreateNode(
               rndFind.m_wsName, rndFind.m_wsCondition,
-              nStart == wsExpression.GetLength(), this);
+              nStart ==
+                  pdfium::base::checked_cast<int32_t>(wsExpression.GetLength()),
+              this);
       if (bCreate) {
         continue;
       } else {
@@ -650,7 +652,9 @@ int32_t CXFA_ScriptContext::ResolveObjects(CXFA_Object* refObject,
         continue;
       }
       if (rndFind.m_dwFlag == XFA_RESOVENODE_RSTYPE_Attribute &&
-          rndFind.m_pScriptAttribute && nStart < wsExpression.GetLength()) {
+          rndFind.m_pScriptAttribute &&
+          nStart <
+              pdfium::base::checked_cast<int32_t>(wsExpression.GetLength())) {
         auto pValue = pdfium::MakeUnique<CFXJSE_Value>(m_pIsolate);
         (rndFind.m_Objects.front()
              ->*(rndFind.m_pScriptAttribute->lpfnCallback))(
@@ -679,7 +683,9 @@ int32_t CXFA_ScriptContext::ResolveObjects(CXFA_Object* refObject,
         bool bCreate =
             m_ResolveProcessor->GetNodeHelper()->ResolveNodes_CreateNode(
                 rndFind.m_wsName, rndFind.m_wsCondition,
-                nStart == wsExpression.GetLength(), this);
+                nStart == pdfium::base::checked_cast<int32_t>(
+                              wsExpression.GetLength()),
+                this);
         if (bCreate) {
           continue;
         } else {