fix EOF handling

src/read.c

@@ -530,6 +530,23 @@ read(pic_state *pic, struct pic_port *port, char c)
 {
   pic_value val;
 
+ retry:
+  val = read_nullable(pic, port, c);
+
+  if (pic_undef_p(val)) {
+    c = next(port);
+    goto retry;
+  }
+
+  return val;
+}
+
+pic_value
+pic_read(pic_state *pic, struct pic_port *port)
+{
+  pic_value val;
+  char c = next(port);
+
  retry:
   c = skip(port, c);
 
@@ -547,16 +564,6 @@ read(pic_state *pic, struct pic_port *port, char c)
   return val;
 }
 
-pic_value
-pic_read(pic_state *pic, struct pic_port *port)
-{
-  char c;
-
-  c = next(port);
-
-  return read(pic, port, c);
-}
-
 pic_value
 pic_read_cstr(pic_state *pic, const char *str)
 {