I discovered that for large designs, running DBWredisplay will take

significant amounts of time even though there is no display to
receive the result.  However, the "suspendall" command only works
if a window exists.  The obvious solution is to set GrDisplayStatus
to DISPLAY_SUSPEND whenever magic is run with the "-dnull" option.
This should help speed up a lot of scripts, in particular where
designs are large.

VERSION

@@ -1 +1 @@
-8.3.112
+8.3.113

graphics/grNull.c

@@ -281,5 +281,8 @@ nullSetDisplay(dispType, outFileName, mouseFileName)
     GrScreenRect.r_xtop = 511;
     GrScreenRect.r_ytop = 483;
 
+    /* Set GrDisplayStatus to force graphics updates to be suspended */
+    GrDisplayStatus = DISPLAY_SUSPEND;
+
     return TRUE;
 }