posix mode changes for interp 1150; fix for varassign redirection; fix for nameref in ${param=value} expansion

CWRU/CWRU.chlog

@@ -5969,3 +5969,35 @@ lib/readline/vi_mode.c
 	- _rl_domove_motion_cleanup: ditto for y/Y
 	- rl_domove_motion_callback: if t/T/;/, fail (return non-zero without
 	  moving point), flag the motion command as having failed (MOVE_FAILED)
+
+				    4/6
+				    ---
+subst.c
+	- command_substitute: save the return status of the child process in
+	  last_command_subst_status; don't assign to last_command_exit_value
+	  in posix mode (posix interp 1150)
+
+execute_cmd.c
+	- execute_null_command: a simple command without a command word but
+	  with command substitutions now returns last_command_subst_status.
+	  It may or may not have already modified $? depending on posix mode
+
+redir.c
+	- redir_varvalue: legal_number validity check should be == 0, not < 0
+	  From a report by Grisha Levit <grishalevit@gmail.com>
+
+				   4/10
+				   ----
+subst.c
+	- parameter_brace_expand_rhs: check for namerefs in the variable name
+	  part of the ${name=word} expansion so we can go back and implement
+	  the POSIX semantics of returning "the final value of parameter."
+	  From a report by Grisha Levit <grishalevit@gmail.com>
+
+sig.c,sig.h
+	- sigpipe_handler: clean up, set $?, and throw to top level on receipt
+	  of a SIGPIPE
+	- termsig_handler: if the variable builtin_catch_sigpipe is set (it's
+	  not set anywhere yet), call sigpipe_handler instead of terminating
+	  the shell. Still need to make sure a sighandler is installed for
+	  SIGPIPE even if initialize_terminating_signals isn't called

doc/bashref.texi

@@ -8561,6 +8561,13 @@ undergoes expansion.
 That means, for example, that a backslash preceding a double quote
 character will escape it and the backslash will be removed.
 
+@item
+Command substitutions don't set the @samp{?} special parameter. The exit
+status of a simple command without a command word is still the exit status
+of the last command substitution that occurred while evaluating the variable
+assignments and redirections in that command, but that does not happen until
+after all of the assignments and redirections.
+
 @end enumerate
 
 There is other @sc{posix} behavior that Bash does not implement by

doc/version.texi

@@ -2,10 +2,10 @@
 Copyright (C) 1988-2023 Free Software Foundation, Inc.
 @end ignore
 
-@set LASTCHANGE Tue Mar 21 11:05:49 EDT 2023
+@set LASTCHANGE Thu Apr  6 11:58:41 EDT 2023
 
 @set EDITION 5.2
 @set VERSION 5.2
 
-@set UPDATED 21 March 2023
-@set UPDATED-MONTH March 2023
+@set UPDATED 6 April 2023
+@set UPDATED-MONTH April 2023

execute_cmd.c

@@ -4123,7 +4123,7 @@ execute_null_command (REDIRECT *redirects, int pipe_in, int pipe_out, int async)
       if (r != 0)
 	return (EXECUTION_FAILURE);
       else if (last_command_subst_pid != NO_PID)
-	return (last_command_exit_value);
+	return (last_command_subst_status);
       else
 	return (EXECUTION_SUCCESS);
     }

parse.y

@@ -5891,7 +5891,7 @@ decode_prompt_string (char *string)
   WORD_LIST *list;
   char *result, *t, *orig_string;
   struct dstack save_dstack;
-  int last_exit_value, last_comsub_pid;
+  int last_exit_value, last_comsub_pid, last_comsub_status;
 #if defined (PROMPT_STRING_DECODE)
   size_t result_size;
   size_t result_index;
@@ -6297,12 +6297,14 @@ not_escape:
     {
       last_exit_value = last_command_exit_value;
       last_comsub_pid = last_command_subst_pid;
+      last_comsub_status = last_command_subst_status;
       list = expand_prompt_string (result, Q_DOUBLE_QUOTES, 0);
       free (result);
       result = string_list (list);
       dispose_words (list);
       last_command_exit_value = last_exit_value;
       last_command_subst_pid = last_comsub_pid;
+      last_command_subst_status = last_comsub_status;
     }
   else
     {

redir.c

@@ -1459,7 +1459,7 @@ redir_varvalue (REDIRECT *redir)
   if (val == 0 || *val == 0)
     return -1;
 
-  if (legal_number (val, &vmax) < 0)
+  if (legal_number (val, &vmax) == 0)
     return -1;
 
   i = vmax;	/* integer truncation */

sig.c

@@ -74,6 +74,8 @@ volatile sig_atomic_t sigterm_received = 0;
 /* Set to the value of any terminating signal received. */
 volatile sig_atomic_t terminating_signal = 0;
 
+volatile int builtin_catch_sigpipe = 0;
+
 /* The environment at the top-level R-E loop.  We use this in
    the case of error return. */
 procenv_t top_level;
@@ -591,6 +593,9 @@ termsig_handler (int sig)
   handling_termsig = terminating_signal;	/* for termsig_sighandler */
   terminating_signal = 0;	/* keep macro from re-testing true. */
 
+  if (builtin_catch_sigpipe)
+    sigpipe_handler (sig);
+
   /* I don't believe this condition ever tests true. */
   if (sig == SIGINT && signal_is_trapped (SIGINT))
     run_interrupt_trap (0);
@@ -714,6 +719,7 @@ sigint_sighandler (int sig)
       set_exit_status (128 + sig);
       throw_to_top_level ();
     }
+
 #if defined (READLINE)
   /* Set the event hook so readline will call it after the signal handlers
      finish executing, so if this interrupted character input we can get
@@ -762,6 +768,15 @@ sigterm_sighandler (int sig)
   SIGRETURN (0);
 }
 
+void
+sigpipe_handler (int sig)
+{
+  handling_termsig = 0;
+  builtin_catch_sigpipe = 0;
+  last_command_exit_value = 128 + sig;
+  throw_to_top_level ();
+}  
+
 /* Signal functions used by the rest of the code. */
 #if !defined (HAVE_POSIX_SIGNALS)
 

sig.h

@@ -108,6 +108,8 @@ extern volatile sig_atomic_t sigterm_received;
 extern int interrupt_immediately;	/* no longer used */
 extern int terminate_immediately;
 
+extern volatile int builtin_catch_sigpipe;	/* not used yet */
+
 /* Functions from sig.c. */
 extern sighandler termsig_sighandler (int);
 extern void termsig_handler (int);
@@ -126,6 +128,8 @@ extern void unset_sigwinch_handler (void);
 
 extern sighandler sigterm_sighandler (int);
 
+extern void sigpipe_handler (int);
+
 /* Functions defined in trap.c. */
 extern SigHandler *set_sigint_handler (void);
 extern SigHandler *trap_to_sighandler (int);

subst.c

@@ -149,6 +149,7 @@ typedef WORD_LIST *EXPFUNC (const char *, int);
 /* Process ID of the last command executed within command substitution. */
 pid_t last_command_subst_pid = NO_PID;
 pid_t current_command_subst_pid = NO_PID;
+int last_command_subst_status = 0;
 
 /* Variables used to keep track of the characters in IFS. */
 SHELL_VAR *ifs_var;
@@ -6723,13 +6724,16 @@ command_substitute (char *string, int quoted, int flags)
 	  istring = optimize_cat_file (cmd->value.Simple->redirects, quoted, flags, &tflag);
 	  if (istring == &expand_param_error)
 	    {
-	      last_command_exit_value = EXECUTION_FAILURE;
+	      last_command_subst_status = EXECUTION_FAILURE;
 	      istring = 0;
 	    }
 	  else
-	    last_command_exit_value = EXECUTION_SUCCESS;	/* compat */
+	    last_command_subst_status = EXECUTION_SUCCESS;	/* compat */
 	  last_command_subst_pid = dollar_dollar_pid;
 
+	  if (posixly_correct == 0)	/* POSIX interp 1150 */
+	    last_command_exit_value = last_command_subst_status;	/* XXX */
+
 	  dispose_command (cmd);	  
 	  ret = alloc_word_desc ();
 	  ret->word = istring;
@@ -6974,10 +6978,13 @@ command_substitute (char *string, int quoted, int flags)
       UNBLOCK_SIGNAL (oset);
 
       current_command_subst_pid = pid;
-      last_command_exit_value = wait_for (pid, JWAIT_NOTERM);
+      last_command_subst_status = wait_for (pid, JWAIT_NOTERM);
       last_command_subst_pid = pid;
       last_made_pid = old_pid;
 
+      if (posixly_correct == 0)		/* POSIX interp 1150 */
+	last_command_exit_value = last_command_subst_status;	/* XXX */
+
 #if defined (JOB_CONTROL)
       /* If last_command_exit_value > 128, then the substituted command
 	 was terminated by a signal.  If that signal was SIGINT, then send
@@ -7626,7 +7633,24 @@ parameter_brace_expand_rhs (char *name, char *value,
 	  return &expand_wdesc_error;
 	}
     }
-    
+  /* We check for this here instead of letting bind_variable do it so we can
+     satisfy the POSIX semantics of returning the final value assigned to the
+     variable, even after assignment transformations (uppercase, lowercase, etc.).
+     We need the final name to get the right value back. */
+  else if ((v = find_variable_last_nameref (name, 0)) && nameref_p (v))
+    {
+      temp = nameref_cell (v);
+      /* shouldn't happen at this point, but... */
+      if (temp == 0 || *temp == 0)
+	{
+	  report_error (_("%s: bad substitution"), name);
+	  free (t1);
+	  dispose_word (w);
+	  return &expand_wdesc_error;
+	}
+      vname = savestring (temp);
+    }
+
   arrayref = 0;
 #if defined (ARRAY_VARS)
   if (valid_array_reference (vname, 0))

subst.h

@@ -350,6 +350,7 @@ extern int expanding_redir;
 extern int inherit_errexit;
 
 extern pid_t last_command_subst_pid;
+extern int last_command_subst_status;
 
 /* Evaluates to 1 if C is a character in $IFS. */
 #define isifs(c)	(ifs_cmap[(unsigned char)(c)] != 0)

tests/nameref.right

@@ -92,6 +92,10 @@ expect <one>
 one
 expect <four>
 four
+expect <X>
+X
+expect <X>
+X
 errors = 0
 1
 2

tests/nameref4.sub

@@ -228,6 +228,20 @@ echo "expect <four>"
 echo $qux
 ckval qux ${bar[3]}
 
+bar=()
+declare -n ref='bar[1]'
+
+echo "expect <X>"
+echo ${ref=X}
+ckval ref ${bar[1]}
+
+unset -n ref
+declare -n ref
+
+echo "expect <X>"
+echo ${ref=X}
+ckval ref ${ref}
+
 # Need to add code and tests for `for' loop nameref variables
 
 echo errors = $errors