Convert string Find methods to return an Optional

The Find and ReverseFind methods for WideString, WideStringC,
ByteString, and ByteStringC have been converted from returning a raw
FX_STRSIZE, to returning Optional<FX_STRSIZE>, so that success/failure
can be indicated without using FX_STRNPOS.

This allows for removing FX_STRNPOS and by association makes the
conversion of FX_STRSIZE to size_t easier, since it forces checking
the return value of Find to be explictly done as well as taking the
error value out of the range of FX_STRSIZE.

New Contains methods have been added for cases where the success or
failure is all the call site to Find cared about, and the actual
position was ignored.

BUG=pdfium:828


Change-Id: Id827e508c8660affa68cc08a13d96121369364b7
Reviewed-on: https://pdfium-review.googlesource.com/11350
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 12 insertions, 13 deletions

diff --git a/xfa/fxfa/cxfa_pdffontmgr.cpp b/xfa/fxfa/cxfa_pdffontmgr.cpp
index af94ee8c82..5872078fdf 100644
--- a/xfa/fxfa/cxfa_pdffontmgr.cpp
+++ b/xfa/fxfa/cxfa_pdffontmgr.cpp
@@ -121,30 +121,29 @@ bool CXFA_PDFFontMgr::PsNameMatchDRFontName(const CFX_ByteStringC& bsPsName,
   CFX_ByteString bsDRName = bsDRFontName;
   bsDRName.Remove('-');
   FX_STRSIZE iPsLen = bsPsName.GetLength();
-  FX_STRSIZE nIndex = bsDRName.Find(bsPsName);
-  if (nIndex != FX_STRNPOS && !bStrictMatch)
+  auto nIndex = bsDRName.Find(bsPsName);
+  if (nIndex.has_value() && !bStrictMatch)
     return true;
 
-  if (nIndex != 0)
+  if (!nIndex.has_value() || nIndex.value() != 0)
     return false;
 
   int32_t iDifferLength = bsDRName.GetLength() - iPsLen;
   if (iDifferLength > 1 || (bBold || bItalic)) {
-    FX_STRSIZE iBoldIndex = bsDRName.Find("Bold");
-    bool bBoldFont = iBoldIndex != FX_STRNPOS;
-    if (bBold != bBoldFont)
+    auto iBoldIndex = bsDRName.Find("Bold");
+    if (bBold != iBoldIndex.has_value())
       return false;
 
-    if (bBoldFont) {
-      iDifferLength =
-          std::min(iDifferLength - 4, bsDRName.GetLength() - iBoldIndex - 4);
+    if (iBoldIndex.has_value()) {
+      iDifferLength = std::min(iDifferLength - 4,
+                               bsDRName.GetLength() - iBoldIndex.value() - 4);
     }
     bool bItalicFont = true;
-    if (bsDRName.Find("Italic") != FX_STRNPOS) {
+    if (bsDRName.Contains("Italic")) {
       iDifferLength -= 6;
-    } else if (bsDRName.Find("It") != FX_STRNPOS) {
+    } else if (bsDRName.Contains("It")) {
       iDifferLength -= 2;
-    } else if (bsDRName.Find("Oblique") != FX_STRNPOS) {
+    } else if (bsDRName.Contains("Oblique")) {
       iDifferLength -= 7;
     } else {
       bItalicFont = false;
@@ -158,7 +157,7 @@ bool CXFA_PDFFontMgr::PsNameMatchDRFontName(const CFX_ByteStringC& bsPsName,
           bsDRTailer == "Regular" || bsDRTailer == "Reg") {
         return true;
       }
-      if (bBoldFont || bItalicFont)
+      if (iBoldIndex.has_value() || bItalicFont)
         return false;
 
       bool bMatch = false;