change to readline callback signal handling; fix message when popping shell function context; handle new terminating signals inside terminating signal handler; fix to pattern substitution with null replacement and null string; fix to alias expansion when we get a SIGINT while entering a command substitution in an interactive shell

execute_cmd.c

@@ -1539,7 +1539,7 @@ execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close)
 	 expansion with `shopt -s expand_alias' to continue to expand
 	 aliases. */
       if (ois != interactive_shell)
-	expand_aliases = 0;
+	expand_aliases = expaliases_flag = 0;
     }
 
   /* Subshells are neither login nor interactive. */
@@ -3627,6 +3627,7 @@ execute_case_command (case_command)
 	  free (pattern);
 
 	  dispose_words (es);
+	  CHECK_TERMSIG;
 
 	  if (match)
 	    {