1 files changed, 6 insertions, 0 deletions
diff --git a/src/Fl_System_Driver.H b/src/Fl_System_Driver.H
index bba6c77ff..b1901b133 100644
--- a/src/Fl_System_Driver.H
+++ b/src/Fl_System_Driver.H
@@ -221,6 +221,12 @@ public:
   virtual void unlock_ring() {}
   virtual double wait(double);                             // must override
   virtual int ready() { return 0; }                        // must override
+  virtual int close_fd(int) {return -1;} // to close a file descriptor
+  // next 2 for support of Fl_SVG_Image
+  virtual int write_nonblocking_fd(int , const unsigned char *&, size_t &) {return 0;}
+  virtual void pipe_support(int &fdread, int &fdwrite, const unsigned char *, size_t ) {
+    fdread = fdwrite = -1;
+  }
 };
 
 #endif // FL_SYSTEM_DRIVER_H