FIXED: number_chars(N, "0' "), addressing #1580.

There may be a more elegant way to solve this.

src/machine/system_calls.rs

@@ -834,6 +834,26 @@ impl MachineState {
     ) -> CallResult {
         let nx = self.store(self.deref(self.registers[2]));
 
+        let mut charcode_space = false;
+        let mut cs = string.chars();
+
+        loop {
+            let c = cs.next();
+
+            if c == None {
+                break;
+            }
+
+            if c == Some('0')
+                && cs.next() == Some('\'')
+                && cs.next() == Some(' ')
+                && cs.next() == None {
+                charcode_space = true;
+                break;
+            }
+        }
+
+        if !charcode_space {
             if let Some(c) = string.chars().last() {
                 if layout_char!(c) {
                     let (line_num, col_num) = string.chars().fold((0, 0), |(line_num, col_num), c| {
@@ -849,6 +869,7 @@ impl MachineState {
                     return Err(self.error_form(err, stub_gen()));
                 }
             }
+        }
 
         let mut dot_buf: [u8; '.'.len_utf8()] = [0u8];
         '.'.encode_utf8(&mut dot_buf);