--- orig/octave/scripts/plot/__errcomm__.m
+++ mod/octave/scripts/plot/__errcomm__.m
@@ -58,8 +58,9 @@
       sz = size (a);
       ndata = 1;
       arg1 = a;
-      while (nargs--)
+      while (nargs)
 	a = varargin{k++};
+        nargs--;
 	if (isstr (a))
 	  fmt = a;
 	  cmd = "__errplot__ (arg1";