Make CPDF_Object::GetString() a virtual method.

fpdfsdk/src/fsdk_baseform.cpp

Index: fpdfsdk/src/fsdk_baseform.cpp
diff --git a/fpdfsdk/src/fsdk_baseform.cpp b/fpdfsdk/src/fsdk_baseform.cpp
index d3742520fa6c358d178a79bc240064f94acf6624..6e14dadb7991cfc59700dc5fc81625a615fc1551 100644
--- a/fpdfsdk/src/fsdk_baseform.cpp
+++ b/fpdfsdk/src/fsdk_baseform.cpp
@@ -596,7 +596,7 @@ void CPDFSDK_Widget::ResetAppearance_PushButton()
 	{
 		if (CPDF_Dictionary* pImageDict = pNormalIcon->GetDict())
 		{
-			if (pImageDict->GetString("Name").IsEmpty())
+			if (pImageDict->GetStringAt("Name").IsEmpty())
 				pImageDict->SetAtString("Name", "ImgA");
 		}
 	}
@@ -605,7 +605,7 @@ void CPDFSDK_Widget::ResetAppearance_PushButton()
 	{
 		if (CPDF_Dictionary* pImageDict = pRolloverIcon->GetDict())
 		{
-			if (pImageDict->GetString("Name").IsEmpty())
+			if (pImageDict->GetStringAt("Name").IsEmpty())
 				pImageDict->SetAtString("Name", "ImgB");
 		}
 	}
@@ -614,7 +614,7 @@ void CPDFSDK_Widget::ResetAppearance_PushButton()
 	{
 		if (CPDF_Dictionary* pImageDict = pDownIcon->GetDict())
 		{
-			if (pImageDict->GetString("Name").IsEmpty())
+			if (pImageDict->GetStringAt("Name").IsEmpty())
 				pImageDict->SetAtString("Name", "ImgC");
 		}
 	}
@@ -1527,7 +1527,7 @@ void CPDFSDK_Widget::AddImageToAppearance(const CFX_ByteString& sAPType, CPDF_St
 
 	if (CPDF_Dictionary* pImageDict = pImage->GetDict())
 	{
-		sImageAlias = pImageDict->GetString("Name");
+		sImageAlias = pImageDict->GetStringAt("Name");
 		if (sImageAlias.IsEmpty())
 			sImageAlias = "IMG";
 	}
@@ -2285,7 +2285,7 @@ FX_BOOL CPDFSDK_InterForm::FDFToURLEncodedData(uint8_t*& pBuf, FX_STRSIZE& nBufS
  			CFX_WideString name;
  			name = pField->GetUnicodeText("T");
  			CFX_ByteString name_b = CFX_ByteString::FromUnicode(name);
- 			CFX_ByteString csBValue = pField->GetString("V");
+ 			CFX_ByteString csBValue = pField->GetStringAt("V");
  			CFX_WideString csWValue = PDF_DecodeText(csBValue);
  			CFX_ByteString csValue_b = CFX_ByteString::FromUnicode(csWValue);
 
@@ -2619,7 +2619,7 @@ CBA_AnnotIterator::CBA_AnnotIterator(CPDFSDK_PageView* pPageView, const CFX_Byte
 	ASSERT(pPDFPage != NULL);
 	ASSERT(pPDFPage->m_pFormDict != NULL);
 
-	CFX_ByteString sTabs = pPDFPage->m_pFormDict->GetString("Tabs");
+	CFX_ByteString sTabs = pPDFPage->m_pFormDict->GetStringAt("Tabs");
 
 	if (sTabs == "R")
 	{