Improve CStdStream const correctness

src/c4group/C4Group.cpp

@@ -1872,7 +1872,7 @@ size_t C4Group::EntrySize(const char *szWildCard)
 	return fsize;
 }
 
-size_t C4Group::AccessedEntrySize() { return p->iCurrFileSize; }
+size_t C4Group::AccessedEntrySize() const { return p->iCurrFileSize; }
 
 unsigned int C4Group::EntryCRC32(const char *szWildCard)
 {

src/c4group/C4Group.h

@@ -211,7 +211,7 @@ public:
 	StdStrBuf GetFullName() const;
 	int EntryCount(const char *szWildCard=nullptr);
 	size_t EntrySize(const char *szWildCard=nullptr);
-	size_t AccessedEntrySize() override; // retrieve size of last accessed entry
+	size_t AccessedEntrySize() const override; // retrieve size of last accessed entry
 	unsigned int EntryCRC32(const char *szWildCard=nullptr);
 	bool IsOpen() const;
 	C4Group *GetMother();

src/c4group/CStdFile.cpp

@@ -348,7 +348,7 @@ int UncompressedFileSize(const char *szFilename)
 	return rval;
 }
 
-size_t CStdFile::AccessedEntrySize()
+size_t CStdFile::AccessedEntrySize() const
 {
 	if (hFile)
 		return FileSize(fileno(hFile));

src/c4group/CStdFile.h

@@ -32,7 +32,7 @@ public:
 	virtual bool Read(void *pBuffer, size_t iSize) = 0;
 	virtual bool Advance(int iOffset) = 0;
 	// Get size. compatible with c4group!
-	virtual size_t AccessedEntrySize() = 0;
+	virtual size_t AccessedEntrySize() const = 0;
 	virtual ~CStdStream() {}
 };
 
@@ -69,7 +69,7 @@ public:
 	bool IsOpen() const { return hFile || hgzFile; }
 	// flush contents to disk
 	inline bool Flush() { if (ModeWrite && BufferLoad) return SaveBuffer(); else return true; }
-	size_t AccessedEntrySize();
+	size_t AccessedEntrySize() const override;
 protected:
 	void ClearBuffer();
 	int LoadBuffer();