include the jpeg headers as extern "C"

Graphics/gl2jpeg.cpp

@@ -2,7 +2,7 @@
  * GL2JPEG, an OpenGL to JPEG Printing Library
  * Copyright (C) 1999-2002  Christophe Geuzaine 
  *
- * $Id: gl2jpeg.cpp,v 1.14 2003-02-12 16:57:38 geuzaine Exp $
+ * $Id: gl2jpeg.cpp,v 1.15 2003-02-17 02:08:46 geuzaine Exp $
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -39,8 +39,10 @@ void create_jpeg(FILE *outfile, int width, int height, int quality){
 #define XMD_H
 #endif
 
+extern "C" {
 #include <jpeglib.h>
 #include <jerror.h>
+}
 
 void my_output_message (j_common_ptr cinfo){
   char buffer[JMSG_LENGTH_MAX];