preserve traps across a failed exec; small changes to how completion options interact; fix a bug with arithmetic for commands and LINENO

CWRU/CWRU.chlog

@@ -2228,3 +2228,54 @@ arrayfunc.c
 	  we don't inadvertently pass a value with bit 2 set, which would
 	  cause an off-by-one error in subscript parsing
 
+				   10/8
+				   ----
+trap.c
+	- restore_traps: inverse of reset_signal_handlers. This understands
+	  how reset_signal_handlers changes the signal disposition while
+	  leaving the trap string in place, and knows how to restore flags
+	  and state based on that preserved trap string and whether or not
+	  the signal is "special" to the shell.
+
+builtins/exec.def
+	- exec_builtin: instead of using restore_original_signals to completely
+	  cancel the traps, call reset_signal_handlers so the trap strings are
+	  preserved. Then if the exec fails (and we're not exiting) we can
+	  look at the trap strings and see how to restore the trap state.
+	  This calls restore_traps after reinitializing the shell signal
+	  handlers, using the trap strings saved by reset_signal_handlers.
+	  Fixes issue with not exiting after a failed exec clearing the EXIT
+	  trap reported by Mark March <march@systempad.org>, using the
+	  approach suggested by Robert Elz <kre@munnari.OZ.AU>
+
+subst.c
+	- expand_declaration_argument: when parsing options that modify
+	  attributes that affect how the value is handled (i, c, u, etc.),
+	  make sure to create an option string and call make_internal_declare
+	  with options that start with a `+' so the attribute is off when
+	  the assignment is performed and changes how the value is expanded.
+	  From a report by Léa Gris <lea.gris@noiraude.net>
+
+lib/readline/complete.c
+	- rl_display_match_list: even if _rl_completion_prefix_display_length
+	  is set to a non-zero value, pass the common prefix length to
+	  fnprint if we've turned on colored completion prefixes; passes
+	  through to fnprint via print_filename
+	- fnprint: add the ellipsis if prefix_bytes exceeds the
+	  _rl_completion_prefix_display_length, add explicit check for
+	  prefix_bytes being longer since print_filename passes it through
+	  if colored-completion-prefix is set. This means that while
+	  completion-prefix-display-length still has precedence over
+	  colored-completion-prefix, it doesn't override it if both are set
+	  and the common prefix length is shorter than
+	  completion-prefix-display-length. From a report by
+	  Christoph Anton Mitterer <calestyo@scientia.net>
+
+				   10/10
+				   -----
+parse.y
+	- parse_dparen: if the last token is FOR, increment word_top and assign
+	  word_lineno like for other for loops. Fixes bug with LINENO after
+	  arithmetic for commands reported by
+	  Tom Coleman <thomas.james.coleman@gmail.com>
+

builtins/exec.def

@@ -215,7 +215,7 @@ exec_builtin (list)
     maybe_save_shell_history ();
 #endif /* HISTORY */
 
-  restore_original_signals ();
+  reset_signal_handlers ();		/* leave trap strings in place */
 
 #if defined (JOB_CONTROL)
   orig_job_control = job_control;	/* XXX - was also interactive_shell */
@@ -261,8 +261,11 @@ failed_exec:
   if (env && env != export_env)
     strvec_dispose (env);
 
-  initialize_traps ();
+  /* If we're not exiting after the exec fails, we restore the shell signal
+     handlers and then modify the signal dispositions based on the trap strings
+     before the failed exec. */
   initialize_signals (1);
+  restore_traps ();
 
 #if defined (JOB_CONTROL)
   if (orig_job_control)

doc/bash.1

@@ -5,12 +5,12 @@
 .\"	Case Western Reserve University
 .\"	chet.ramey@case.edu
 .\"
-.\"	Last Change: Fri Oct  1 14:20:30 EDT 2021
+.\"	Last Change: Fri Oct  8 14:10:30 EDT 2021
 .\"
 .\" bash_builtins, strip all but Built-Ins section
 .if \n(zZ=1 .ig zZ
 .if \n(zY=1 .ig zY
-.TH BASH 1 "2021 October 1" "GNU Bash 5.1"
+.TH BASH 1 "2021 October 8" "GNU Bash 5.1"
 .\"
 .\" There's some problem with having a `@'
 .\" in a tagged paragraph with the BSD man macros.
@@ -11403,6 +11403,10 @@ The individual per-interactive-shell startup file
 .FN ~/.bash_logout
 The individual login shell cleanup file, executed when a login shell exits
 .TP
+.FN ~/.bash_history
+The default value of \fBHISTFILE\fP, the file in which bash saves the
+command history
+.TP
 .FN ~/.inputrc
 Individual \fIreadline\fP initialization file
 .PD

lib/readline/complete.c

@@ -835,7 +835,8 @@ fnprint (const char *to_print, int prefix_bytes, const char *real_pathname)
     colored_stat_start (real_pathname);
 #endif
 
-  if (prefix_bytes && _rl_completion_prefix_display_length > 0)
+  if (prefix_bytes && _rl_completion_prefix_display_length > 0 &&
+      prefix_bytes > _rl_completion_prefix_display_length)
     {
       char ellipsis;
 
@@ -1548,7 +1549,7 @@ rl_display_match_list (char **matches, int len, int max)
 
       if (common_length > _rl_completion_prefix_display_length && common_length > ELLIPSIS_LEN)
 	max -= common_length - ELLIPSIS_LEN;
-      else
+      else if (_rl_colored_completion_prefix <= 0)
 	common_length = sind = 0;
     }
 #if defined (COLOR_SUPPORT)

lib/readline/terminal.c

@@ -386,8 +386,12 @@ _rl_sigwinch_resize_terminal (void)
 void
 rl_resize_terminal (void)
 {
+  int width, height;
+
+  width = _rl_screenwidth;
+  height = _rl_screenheight;
   _rl_get_screen_size (fileno (rl_instream), 1);
-  if (_rl_echoing_p)
+  if (_rl_echoing_p && (width != _rl_screenwidth || height != _rl_screenheight))
     {
       if (CUSTOM_REDISPLAY_FUNC ())
 	rl_forced_update_display ();

parse.y

@@ -4348,7 +4348,9 @@ parse_dparen (c)
 #if defined (ARITH_FOR_COMMAND)
   if (last_read_token == FOR)
     {
-      arith_for_lineno = line_number;
+      if (word_top < MAX_CASE_NEST)
+	word_top++;
+      arith_for_lineno = word_lineno[word_top] = line_number;
       cmdtyp = parse_arith_cmd (&wval, 0);
       if (cmdtyp == 1)
 	{

subst.c

@@ -12132,10 +12132,13 @@ expand_declaration_argument (tlist, wcmd)
   memset (omap, '\0', sizeof (omap));
   for (l = wcmd->next; l != tlist; l = l->next)
     {
-      if (l->word->word[0] != '-')
+      int optchar;
+
+      if (l->word->word[0] != '-' && l->word->word[0] != '+')
 	break;	/* non-option argument */
       if (l->word->word[0] == '-' && l->word->word[1] == '-' && l->word->word[2] == 0)
 	break;	/* -- signals end of options */
+      optchar = l->word->word[0];
       for (oind = 1; l->word->word[oind]; oind++)
 	switch (l->word->word[oind])
 	  {
@@ -12147,7 +12150,7 @@ expand_declaration_argument (tlist, wcmd)
 	    case 'c':
 	      omap[l->word->word[oind]] = 1;
 	      if (opti == 0)
-		opts[opti++] = '-';
+		opts[opti++] = optchar;
 	      break;
 	    default:
 	      break;

tests/RUN-ONE-TEST

@@ -1,4 +1,4 @@
-BUILD_DIR=/usr/local/build/chet/bash/bash-current
+BUILD_DIR=/usr/local/build/bash/bash-current
 THIS_SH=$BUILD_DIR/bash
 PATH=$PATH:$BUILD_DIR
 

tests/array.right

@@ -381,6 +381,8 @@ strlen(4four) = 5
 1 2 0 3
 1 2 0 3
 1 2 0 3
+declare -ai arr=([0]="2" [1]="4" [2]="6")
+declare -a arr=([0]="hello" [1]="world")
 foo index 1: ok
 foo index 2: ok
 foo: implicit reference to element 0: ok

tests/array15.sub

@@ -35,3 +35,18 @@ func()
 
 func
 echo "${foo[@]}" 
+
+unset foo
+
+# test options to declare that disable attributes that affect how values
+# are expanded
+#
+# we already handle options that set attributes specially, so we should
+# handle attributes that unset those attributes specially as well
+
+unset arr
+declare -i -a arr=(1+1 2+2 3+3)
+declare -p arr 
+
+declare +i arr=(hello world)
+declare -p arr

tests/exec.right

@@ -20,8 +20,17 @@ after exec1.sub: one two three
 126
 0
 this is bashenv
-./exec3.sub: line 3: /tmp/bash-notthere: No such file or directory
-127
+trap -- 'echo EXIT' EXIT
+trap -- '' SIGTERM
+trap -- 'echo USR1' SIGUSR1
+USR1
+./exec3.sub: line 27: /tmp/bash-notthere: No such file or directory
+./exec3.sub: after failed exec: 127
+trap -- 'echo EXIT' EXIT
+trap -- '' SIGTERM
+trap -- 'echo USR1' SIGUSR1
+USR1
+EXIT
 ./execscript: line 71: notthere: No such file or directory
 127
 ./execscript: line 74: notthere: No such file or directory

tests/exec3.sub

@@ -1,6 +1,37 @@
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# test the behavior of `execfail' not exiting an interactive shell
+# added tests for changes in 10/2021 for preserving the traps across a failed
+# exec
+
 shopt -s execfail
 
-exec /tmp/bash-notthere
-# make sure we're still around
-echo $?
+trap 'echo EXIT' EXIT 
+trap 'echo USR1' USR1
+trap '' TERM
+trap
 
+kill -s USR1 $$		# should run the trap
+
+exec /tmp/bash-notthere
+
+# make sure we're still around
+echo $0: after failed exec: $?
+
+trap
+kill -s USR1 $$		# should run the trap
+kill -s TERM $$		# should still be ignored
+
+# this should run the exit trap
+exit 0

tests/new-exp16.sub

@@ -1,3 +1,17 @@
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
 HOME=/homes/chet
 string=abcdefg
 set -- a b c

trap.c

@@ -83,6 +83,7 @@ static void free_trap_string (int);
 static void reset_signal (int);
 static void restore_signal (int);
 static void reset_or_restore_signal_handlers (sh_resetsig_func_t *);
+static void reinit_trap (int);
 
 static void trap_if_untrapped (int, char *);
 
@@ -1365,6 +1366,77 @@ restore_original_signals ()
   reset_or_restore_signal_handlers (restore_signal);
 }
 
+/* Change the flags associated with signal SIG without changing the trap
+   string. The string is TRAP_LIST[SIG] if we need it. */
+static void
+reinit_trap (sig)
+     int sig;
+{
+  sigmodes[sig] |= SIG_TRAPPED;
+  if (trap_list[sig] == (char *)IGNORE_SIG)
+    sigmodes[sig] |= SIG_IGNORED;
+  else
+    sigmodes[sig] &= ~SIG_IGNORED;
+  if (sigmodes[sig] & SIG_INPROGRESS)
+    sigmodes[sig] |= SIG_CHANGED;
+}
+
+/* Undo the effects of reset_signal_handlers(), which unsets the traps but
+   leaves the trap strings in place. This understands how reset_signal_handlers
+   works. */
+void
+restore_traps ()
+{
+  char *trapstr;
+  int i;
+
+  /* Take care of the exit trap first. If TRAP_LIST[0] is non-null, the trap
+     has been set. */
+  trapstr = trap_list[EXIT_TRAP];
+  if (trapstr)
+    reinit_trap (EXIT_TRAP);
+
+  /* Then DEBUG, RETURN, and ERROR. TRAP_LIST[N] == 0 if these signals are
+     not trapped. This knows what reset_signal_handlers does for these traps */
+  trapstr = trap_list[DEBUG_TRAP];
+  if (trapstr && function_trace_mode == 0)
+    reinit_trap (DEBUG_TRAP);
+  trapstr = trap_list[RETURN_TRAP];
+  if (trapstr && function_trace_mode == 0)
+    reinit_trap (RETURN_TRAP);
+  trapstr = trap_list[ERROR_TRAP];
+  if (trapstr && error_trace_mode == 0)
+    reinit_trap (ERROR_TRAP);
+
+  /* And finally all the `real' signals. reset_signal_handlers just changes the
+     signal handler for these signals, leaving the trap value in place. We
+     intuit what to do based on that value. We assume that signals marked as
+     SIG_SPECIAL are reinitialized by initialize_signals (), so we don't
+     change the signal handler unless the signal is supposed to be ignored. */
+  for (i = 1; i < NSIG; i++)
+    {
+      trapstr = trap_list[i];
+      if (sigmodes[i] & SIG_SPECIAL)
+	{
+	  if (trapstr && trapstr != (char *)DEFAULT_SIG)
+	    reinit_trap (i);
+	  if (trapstr == (char *)IGNORE_SIG && (sigmodes[i] & SIG_NO_TRAP) == 0)
+	    set_signal_handler (i, SIG_IGN);
+	}
+      else if (trapstr == (char *)IGNORE_SIG)
+	{
+	  reinit_trap (i);
+	  if ((sigmodes[i] & SIG_NO_TRAP) == 0)
+	    set_signal_handler (i, SIG_IGN);
+	}
+      else if (trapstr != (char *)DEFAULT_SIG)
+        /* set_signal duplicates the string argument before freeing it. */
+	set_signal (i, trapstr);
+
+      pending_traps[i] = 0;	/* XXX */
+    }
+}
+
 /* If a trap handler exists for signal SIG, then call it; otherwise just
    return failure.  Returns 1 if it called the trap handler. */
 int

trap.h

@@ -98,6 +98,7 @@ extern void run_return_trap PARAMS((void));
 extern void free_trap_strings PARAMS((void));
 extern void reset_signal_handlers PARAMS((void));
 extern void restore_original_signals PARAMS((void));
+extern void restore_traps PARAMS((void));
 
 extern void get_original_signal PARAMS((int));
 extern void get_all_original_signals PARAMS((void));