$ diff -u Marlin Marlin-new
Common subdirectories: Marlin/Gen7 and Marlin-new/Gen7
Common subdirectories: Marlin/hardware and Marlin-new/hardware
diff -u Marlin/Marlin.pde Marlin-new/Marlin.pde
--- Marlin/Marlin.pde   2012-04-30 04:37:50.000000000 -0700
+++ Marlin-new/Marlin.pde       2012-05-07 13:28:34.631726700 -0700
@@ -1257,6 +1257,11 @@
       PID_autotune(temp);
     }
     break;
+    case 304: //allong long extrude
+    {
+      allow_long_extrudes(true);
+    }
+    break;
     case 400: // finish all moves
     {
       st_synchronize();
diff -u Marlin/planner.cpp Marlin-new/planner.cpp
--- Marlin/planner.cpp  2012-04-30 04:37:50.000000000 -0700
+++ Marlin-new/planner.cpp      2012-05-07 13:27:34.118265500 -0700
@@ -101,6 +101,7 @@
 //===========================================================================
 #ifdef PREVENT_DANGEROUS_EXTRUDE
   bool allow_cold_extrude=false;
+  bool allow_long_extrude=false;
 #endif
 #ifdef XY_FREQUENCY_LIMIT
   // Used for the frequency limit
@@ -495,7 +496,7 @@
       SERIAL_ECHO_START;
       SERIAL_ECHOLNPGM(MSG_ERR_COLD_EXTRUDE_STOP);
     }
-    if(labs(target[E_AXIS]-position[E_AXIS])>axis_steps_per_unit[E_AXIS]*EXTRUDE_MAXLENGTH)
+    if(labs(target[E_AXIS]-position[E_AXIS])>axis_steps_per_unit[E_AXIS]*EXTRUDE_MAXLENGTH && !allow_long_extrude)
     {
       position[E_AXIS]=target[E_AXIS]; //behave as if the move really took place, but ignore E part
       SERIAL_ECHO_START;
@@ -806,6 +807,13 @@
  return (block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1);
 }

+void allow_long_extrudes(bool allow)
+{
+  #ifdef PREVENT_DANGEROUS_EXTRUDE
+    allow_long_extrude=allow;
+  #endif
+}
+
 void allow_cold_extrudes(bool allow)
 {
   #ifdef PREVENT_DANGEROUS_EXTRUDE