Return code of coproc when NAME is not a legal_identifier

[Eduardo A . Bustamante López]

The manual is clear on this:

  Since the coprocess is created as an asynchronous command, the coproc
  command always returns success

I'd argue that it should return an error code for this particular case
though:

  $ bash -c 'coproc % { :; }; echo $?'
  bash: `%': not a valid identifier
  0


The `execute_coproc' function _seems_ to try to return an error code for this
case (by the way, the value of `invert' is undefined at this point):

  2301   /* XXX - expand coproc name without splitting -- bash-5.0 */
  2302   /* could make this dependent on a shopt option */
  2303   name = expand_string_unsplit_to_string (command->value.Coproc->name, 
0);
  2304   /* Optional check -- bash-5.0. */
  2305   if (legal_identifier (name) == 0)
  2306     {
  2307       internal_error (_("`%s': not a valid identifier"), name);
  2308       return (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
  2309     }
  2310   else
  2311     {
  2312       free (command->value.Coproc->name);
  2313       command->value.Coproc->name = name;
  2314     }


The following patch fixes this (coproc returns $? = 1 when `NAME' is not a
legal identifier), although I'm not convinced about the quality of this patch.


dualbus@debian:~/src/gnu/bash$ git diff
diff --git a/execute_cmd.c b/execute_cmd.c
index 0183a105..ab022bdb 100644
--- a/execute_cmd.c
+++ b/execute_cmd.c
@@ -597,8 +597,9 @@ execute_command_internal (command, asynchronous, pipe_in, 
pipe_out,
     return (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, 
fds_to_close));
 
 #if defined (COPROCESS_SUPPORT)
-  if (command->type == cm_coproc)
-    return (execute_coproc (command, pipe_in, pipe_out, fds_to_close));
+  if (command->type == cm_coproc) {
+    return (last_command_exit_value = execute_coproc (command, pipe_in, 
pipe_out, fds_to_close));
+  }
 #endif
 
   user_subshell = command->type == cm_subshell || ((command->flags & 
CMD_WANT_SUBSHELL) != 0);
@@ -2298,6 +2299,8 @@ execute_coproc (command, pipe_in, pipe_out, fds_to_close)
   coproc_init (&sh_coproc);
 #endif
 
+  invert = (command->flags & CMD_INVERT_RETURN) != 0;
+
   /* XXX - expand coproc name without splitting -- bash-5.0 */
   /* could make this dependent on a shopt option */
   name = expand_string_unsplit_to_string (command->value.Coproc->name, 0);
@@ -2313,7 +2316,6 @@ execute_coproc (command, pipe_in, pipe_out, fds_to_close)
       command->value.Coproc->name = name;
     }
 
-  invert = (command->flags & CMD_INVERT_RETURN) != 0;
   command_string_index = 0;
   tcmd = make_command_string (command);




This came up as a warning from cppcheck:

  [../bash/execute_cmd.c:2308]: (error) Uninitialized variable: invert

-- 
Eduardo Bustamante
https://dualbus.me/