deal with errno out of range when reading it from the master

sql/slave.cc:
  print expected error number
sql/unireg.h:
  sanity check for errno range in ER(X)

sql/slave.cc

@@ -916,9 +916,10 @@ static int exec_event(THD* thd, NET* net, MASTER_INFO* mi, int event_len)
 		(actual_error = thd->net.last_errno) && expected_error)
 	      {
 		const char* errmsg = "Slave: did not get the expected error\
- running query from master - expected: '%s', got '%s'"; 
-		sql_print_error(errmsg, ER(expected_error),
-				actual_error ? thd->net.last_error:"no error"
+ running query from master - expected: '%s'(%d), got '%s'(%d)"; 
+		sql_print_error(errmsg, ER(expected_error), expected_error,
+				actual_error ? thd->net.last_error:"no error",
+				actual_error
 				);
 		thd->query_error = 1;
 	      }

sql/unireg.h

@@ -37,7 +37,8 @@
 #define SHAREDIR	"share/"
 #endif
 
-#define ER(X) errmesg[(X)-1000]
+#define ER(X) ((X) >= 1000 && (X) < ER_ERROR_MESSAGES + 1000) ? \
+ errmesg[(X)-1000] : "Invalid error code"
 
 #define ERRMAPP 1				/* Errormap f|r my_error */
 #define LIBLEN FN_REFLEN-FN_LEN			/* Max l{ngd p} dev */