touchup to last fix

sql/log.cc:
  moved mutex back to after is_open() test,
  but still protecting name dereference (the real problem)

sql/log.cc

@@ -513,44 +513,46 @@ bool MYSQL_LOG::is_active(const char* log_file_name)
 
 void MYSQL_LOG::new_file(bool inside_mutex)
 {
+  if (!is_open())
+    return;
+
   if (!inside_mutex)
     VOID(pthread_mutex_lock(&LOCK_log));
-  if (is_open())
-  {
-    char new_name[FN_REFLEN], *old_name=name;
+
+  char new_name[FN_REFLEN], *old_name = name;
  
-    if (!no_rotate)
+  if (!no_rotate)
+  {
+    /*
+      only rotate open logs that are marked non-rotatable
+      (binlog with constant name are non-rotatable)
+    */
+    if (generate_new_name(new_name, name))
+    {
+      if (!inside_mutex)
+	VOID(pthread_mutex_unlock(&LOCK_log));
+      return;					// Something went wrong
+    }
+    if (log_type == LOG_BIN)
     {
       /*
-	only rotate open logs that are marked non-rotatable
-	(binlog with constant name are non-rotatable)
+	We log the whole file name for log file as the user may decide
+	to change base names at some point.
       */
-      if (generate_new_name(new_name, name))
-      {
-	if (!inside_mutex)
-	  VOID(pthread_mutex_unlock(&LOCK_log));
-	return;					// Something went wrong
-      }
-      if (log_type == LOG_BIN)
-      {
-	/*
-	  We log the whole file name for log file as the user may decide
-	  to change base names at some point.
-	*/
-	Rotate_log_event r(new_name+dirname_length(new_name));
-	r.write(&log_file);
-	VOID(pthread_cond_broadcast(&COND_binlog_update));
-      }
+      Rotate_log_event r(new_name+dirname_length(new_name));
+      r.write(&log_file);
+      VOID(pthread_cond_broadcast(&COND_binlog_update));
     }
-    else
-      strmov(new_name, old_name);		// Reopen old file name
-    name=0;
-    close();
-    open(old_name, log_type, new_name);
-    my_free(old_name,MYF(0));
-    last_time=query_start=0;
-    write_error=0;
   }
+  else
+    strmov(new_name, old_name);		// Reopen old file name
+  name=0;
+  close();
+  open(old_name, log_type, new_name);
+  my_free(old_name,MYF(0));
+  last_time=query_start=0;
+  write_error=0;
+
   if (!inside_mutex)
     VOID(pthread_mutex_unlock(&LOCK_log));
 }
@@ -564,8 +566,8 @@ bool MYSQL_LOG::write(THD *thd,enum enum_server_command command,
     int error=0;
     VOID(pthread_mutex_lock(&LOCK_log));
 
-    /* Test if someone closed after the is_open test */
-    if (log_type != LOG_CLOSED)
+    /* Test if someone closed between the is_open test and lock */
+    if (is_open())
     {
       time_t skr;
       ulong id;