Remove CPDF_Object::GetConstString and overrides

GetConstString() has sharp edges in that when applied to
a CPDF_Number, it must return null whereas GetString() returns
a the stringified number, because of the inability to
control the lifetime of the underlying allocated string.

Deleting this method showed several places where we
actually wanted a *String, not a *StringC, so we were
re-allocating a string we already had.

Review URL: https://codereview.chromium.org/1879683002

1 files changed, 4 insertions, 3 deletions

diff --git a/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index ba2901df24..654c9350a9 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -736,9 +736,10 @@ void CPDF_StreamContentParser::Handle_ExecuteXObject() {
     return;
   }
 
-  CFX_ByteStringC type = pXObject->GetDict()
-                             ? pXObject->GetDict()->GetConstStringBy("Subtype")
-                             : CFX_ByteStringC();
+  CFX_ByteString type;
+  if (pXObject->GetDict())
+    type = pXObject->GetDict()->GetStringBy("Subtype");
+
   if (type == "Image") {
     if (m_Options.m_bTextOnly) {
       return;