demand_copy_C_string NUL check

[Alan Modra]

Making sure strings don't contain '\0' can't be that important; This
bug has been around since 1991.

	* read.c (demand_copy_C_string): Really check for embedded zeros.

diff --git a/gas/read.c b/gas/read.c
index ede811b0a0..3e76065328 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -5743,12 +5743,12 @@ demand_copy_C_string (int *len_pointer)
 
       for (len = *len_pointer; len > 0; len--)
 	{
-	  if (*s == 0)
+	  if (s[len - 1] == 0)
 	    {
 	      s = 0;
-	      len = 1;
 	      *len_pointer = 0;
 	      as_bad (_("this string may not contain \'\\0\'"));
+	      break;
 	    }
 	}
     }

-- 
Alan Modra
Australia Development Lab, IBM