public: crtlib: add safe COM_DefaultExtension and COM_ReplaceExtension

public/crtlib.c

@@ -714,7 +714,7 @@ void COM_StripExtension( char *path )
 COM_DefaultExtension
 ==================
 */
-void COM_DefaultExtension( char *path, const char *extension )
+void COM_DefaultExtension( char *path, const char *extension, size_t size )
 {
 	const char	*src;
 	size_t		 len;
@@ -731,7 +731,7 @@ void COM_DefaultExtension( char *path, const char *extension )
 		src--;
 	}
 
-	Q_strcpy( &path[len], extension );
+	Q_strncpy( &path[len], extension, size - len );
 }
 
 /*
@@ -739,10 +739,10 @@ void COM_DefaultExtension( char *path, const char *extension )
 COM_ReplaceExtension
 ==================
 */
-void COM_ReplaceExtension( char *path, const char *extension )
+void COM_ReplaceExtension( char *path, const char *extension, size_t size )
 {
 	COM_StripExtension( path );
-	COM_DefaultExtension( path, extension );
+	COM_DefaultExtension( path, extension, size );
 }
 
 /*

public/crtlib.h

@@ -79,15 +79,14 @@ const byte *Q_memmem( const byte *haystack, size_t haystacklen, const byte *need
 const char *Q_timestamp( int format );
 int Q_vsnprintf( char *buffer, size_t buffersize, const char *format, va_list args );
 int Q_snprintf( char *buffer, size_t buffersize, const char *format, ... ) _format( 3 );
-int Q_sprintf( char *buffer, const char *format, ... ) _format( 2 );
 #define Q_strpbrk strpbrk
 void COM_StripColors( const char *in, char *out );
 #define Q_memprint( val ) Q_pretifymem( val, 2 )
 char *Q_pretifymem( float value, int digitsafterdecimal );
 void COM_FileBase( const char *in, char *out, size_t size );
 const char *COM_FileExtension( const char *in );
-void COM_DefaultExtension( char *path, const char *extension );
-void COM_ReplaceExtension( char *path, const char *extension );
+void COM_DefaultExtension( char *path, const char *extension, size_t size );
+void COM_ReplaceExtension( char *path, const char *extension, size_t size );
 void COM_ExtractFilePath( const char *path, char *dest );
 const char *COM_FileWithoutPath( const char *in );
 void COM_StripExtension( char *path );