]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
cli: modern_hush: Add upstream commits up to 2nd October 2023.
authorFrancis Laniel <francis.laniel@amarulasolutions.com>
Fri, 22 Dec 2023 21:02:42 +0000 (22:02 +0100)
committerTom Rini <trini@konsulko.com>
Thu, 28 Dec 2023 17:02:56 +0000 (12:02 -0500)
This commit adds the following hush busybox upstream commits:
791b222dd55d ("sleep: fix "sleep -- ARGS"")
5353df91cba7 ("Update applet size estimates")
e41e481fd571 ("hush: fix a compile failure")
07a95cfcabb0 ("ash: disable check for "good" function name, bash does not check this")
e5692e2342c6 ("hush: quote values in "readonly" output")
96769486e20f ("shell: move varcmp() to shell_common.h and use it in hush")
bab8828b0dad ("hush: fix expansion of space in "a=${a:+$a }c" construct")
b5be8da350b5 ("hush: make "false" built-in")
6824298ab4d3 ("hush: fix ELIF cmd1;cmd2 THEN ... not executing cmd2, closes 15571")
3a7f00eadcf4 ("hush: add comment about abort on syntax error %{^}")
acae889dd972 ("ash,hush: tab completion of functions and aliases")
90b607d79a13 ("hush: quote variable values printed by "set" (match ash behavior)")
6748e6494c22 ("hush (NOMMU): fix LINENO in execed children")
fd5fb2d2b596 ("hush: speed up "big heredoc" code")
1409432d072e ("hush: add TODO comment")
93ae7464e6e4 ("hush: restore SIGHUP handling, this time explain why we do what we do")
1fdb33bd07e5 ("hush: restore tty pgrp on SIGHUP")
6101b6d3eaa0 ("hush: remove special handling of SIGHUP")
93e0898c663a ("shell: fix SIGWINCH and SIGCHLD (in hush) interrupting line input, closes 15256")
969e00816835 ("hush: code shrink")
27be0e8cfeb6 ("shell: fix compile failures in some configs")
7d1c7d833785 ("ash,hush: use HOME for tab completion and prompts")
21afddefd258 ("hush: fix "error: invalid preprocessing directive ##"")
e53c7dbafc78 ("hush: fix set -n to act immediately, not just after run_list()")
574b9c446da1 ("hush: fix var_LINENO3.tests failure")
49bcf9f40cff ("hush: speed up ${x//\*/|} too")
53b2fdcdba4c ("*: add NOINLINEs where code noticeably shrinks")
7c3e96d4b3d4 ("shell: use more compact SHELL_ASH / HUSH config defines. no code changes")
62f1eed1e191 ("hush: in a comment, document what -i might be doing")
aaf3d5ba74c5 ("shell: tweak --help")
db5546ca1018 ("libbb: code shrink: introduce and use [_]exit_SUCCESS()")
931c55f9e2b4 ("libbb: invert the meaning of SETUP_ENV_NO_CHDIR -> SETUP_ENV_CHDIR")
12566e7f9b5e ("ash,hush: fix handling of SIGINT while waiting for interactive input")
987be932ed3c ("*: slap on a few ALIGN_PTR where appropriate")

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
common/cli_hush_modern.c
common/cli_hush_upstream.c

index fb578c38535926659e75b55aad629353eedec502..9a1bc977d5b53766e7610ba64dc661642398316a 100644 (file)
@@ -26,7 +26,7 @@
 /*
  * BusyBox Version: UPDATE THIS WHEN PULLING NEW UPSTREAM REVISION!
  */
-#define BB_VER                 "1.34.0.git37460f5daff9"
+#define BB_VER                 "1.35.0.git7d1c7d833785"
 
 /*
  * Define hush features by the names used upstream.
@@ -236,6 +236,24 @@ static size_t list_size(char **list)
        return size;
 }
 
+static int varcmp(const char *p, const char *q)
+{
+       int c, d;
+
+       while ((c = *p) == (d = *q)) {
+               if (c == '\0' || c == '=')
+                       goto out;
+               p++;
+               q++;
+       }
+       if (c == '=')
+               c = '\0';
+       if (d == '=')
+               d = '\0';
+out:
+       return c - d;
+}
+
 struct in_str;
 static int u_boot_cli_readline(struct in_str *i);
 
index 748edc9d2fd48ab606e55103c259bd0ad073813e..ca40bbb2cd8ae3c7aa8c4a3b60418ebb87d658e3 100644 (file)
@@ -91,7 +91,7 @@
  * in word = GLOB, quoting should be significant on char-by-char basis: a*cd"*"
  */
 //config:config HUSH
-//config:      bool "hush (68 kb)"
+//config:      bool "hush (70 kb)"
 //config:      default y
 //config:      select SHELL_HUSH
 //config:      help
  * therefore we don't show them either.
  */
 //usage:#define hush_trivial_usage
-//usage:       "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]"
+//usage:       "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE ARGS | -s ARGS]"
 //usage:#define hush_full_usage "\n\n"
 //usage:       "Unix shell interpreter"
 
 # define F_DUPFD_CLOEXEC F_DUPFD
 #endif
 
-#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !(ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH)
+#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !ENABLE_SHELL_ASH
 # include "embedded_scripts.h"
 #else
 # define NUM_SCRIPTS 0
@@ -573,7 +573,7 @@ enum {
 #define NULL_O_STRING { NULL }
 
 #ifndef debug_printf_parse
-static const char *const assignment_flag[] = {
+static const char *const assignment_flag[] ALIGN_PTR = {
        "MAYBE_ASSIGNMENT",
        "DEFINITELY_ASSIGNMENT",
        "NOT_ASSIGNMENT",
@@ -957,6 +957,7 @@ struct globals {
 #if ENABLE_HUSH_INTERACTIVE
        smallint promptmode; /* 0: PS1, 1: PS2 */
 #endif
+       /* set by signal handler if SIGINT is received _and_ its trap is not set */
        smallint flag_SIGINT;
 #ifndef __U_BOOT__
 #if ENABLE_HUSH_LOOPS
@@ -1133,6 +1134,7 @@ static int builtin_export(char **argv) FAST_FUNC;
 #if ENABLE_HUSH_READONLY
 static int builtin_readonly(char **argv) FAST_FUNC;
 #endif
+static int builtin_false(char **argv) FAST_FUNC;
 #if ENABLE_HUSH_JOB
 static int builtin_fg_bg(char **argv) FAST_FUNC;
 static int builtin_jobs(char **argv) FAST_FUNC;
@@ -1233,6 +1235,7 @@ static const struct built_in_command bltins1[] ALIGN_PTR = {
 #if ENABLE_HUSH_EXPORT
        BLTIN("export"   , builtin_export  , "Set environment variables"),
 #endif
+       BLTIN("false"    , builtin_false   , NULL),
 #if ENABLE_HUSH_JOB
        BLTIN("fg"       , builtin_fg_bg   , "Bring job to foreground"),
 #endif
@@ -1506,6 +1509,7 @@ static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
 {
        bb_error_msg("syntax error: unterminated %s", s);
 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
+// (but bash --posix, or if bash is run as "sh", does terminate in script, so maybe uncomment this?)
 //     die_if_script();
 }
 
@@ -1917,7 +1921,13 @@ static void restore_G_args(save_arg_t *sv, char **argv)
  * SIGQUIT: ignore
  * SIGTERM (interactive): ignore
  * SIGHUP (interactive):
- *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
+ *    Send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit.
+ *    Kernel would do this for us ("orphaned process group" handling
+ *    according to POSIX) if we are a session leader and thus our death
+ *    frees the controlling tty, but to be bash-compatible, we also do it
+ *    for every interactive shell's death by SIGHUP.
+ *    (Also, we need to restore tty pgrp, otherwise e.g. Midnight Commander
+ *    backgrounds when hush started from it gets killed by SIGHUP).
  * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
  *    Note that ^Z is handled not by trapping SIGTSTP, but by seeing
  *    that all pipe members are stopped. Try this in bash:
@@ -2033,6 +2043,14 @@ enum {
 static void record_pending_signo(int sig)
 {
        sigaddset(&G.pending_set, sig);
+#if ENABLE_FEATURE_EDITING
+       if (sig != SIGCHLD
+        || (G_traps && G_traps[SIGCHLD] && G_traps[SIGCHLD][0])
+        /* ^^^ if SIGCHLD, interrupt line reading only if it has a trap */
+       ) {
+               bb_got_signal = sig; /* for read_line_input: "we got a signal" */
+       }
+#endif
 #if ENABLE_HUSH_FAST
        if (sig == SIGCHLD) {
                G.count_SIGCHLD++;
@@ -2264,20 +2282,27 @@ static int check_and_run_traps(void)
                        break;
 #if ENABLE_HUSH_JOB
                case SIGHUP: {
-//TODO: why are we doing this? ash and dash don't do this,
-//they have no handler for SIGHUP at all,
-//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
-                       struct pipe *job;
-                       debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
-                       /* bash is observed to signal whole process groups,
-                        * not individual processes */
-                       for (job = G.job_list; job; job = job->next) {
-                               if (job->pgrp <= 0)
-                                       continue;
-                               debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
-                               if (kill(- job->pgrp, SIGHUP) == 0)
-                                       kill(- job->pgrp, SIGCONT);
+                       /* if (G_interactive_fd) - no need to check, the handler
+                        * is only installed if we *are* interactive */
+                       {
+                               /* bash compat: "Before exiting, an interactive
+                                * shell resends the SIGHUP to all jobs, running
+                                * or stopped.  Stopped jobs are sent SIGCONT
+                                * to ensure that they receive the SIGHUP."
+                                */
+                               struct pipe *job;
+                               debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
+                               /* bash is observed to signal whole process groups,
+                                * not individual processes */
+                               for (job = G.job_list; job; job = job->next) {
+                                       if (job->pgrp <= 0)
+                                               continue;
+                                       debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
+                                       if (kill(- job->pgrp, SIGHUP) == 0)
+                                               kill(- job->pgrp, SIGCONT);
+                               }
                        }
+                       /* this restores tty pgrp, then kills us with SIGHUP */
                        sigexit(SIGHUP);
                }
 #endif
@@ -2326,14 +2351,14 @@ static const char *get_cwd(int force)
 /*
  * Shell and environment variable support
  */
-static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
+static struct variable **get_ptr_to_local_var(const char *name)
 {
        struct variable **pp;
        struct variable *cur;
 
        pp = &G.top_var;
        while ((cur = *pp) != NULL) {
-               if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
+               if (varcmp(cur->varstr, name) == 0)
                        return pp;
                pp = &cur->next;
        }
@@ -2343,21 +2368,20 @@ static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
 static const char* FAST_FUNC get_local_var_value(const char *name)
 {
        struct variable **vpp;
-       unsigned len = strlen(name);
 
        if (G.expanded_assignments) {
                char **cpp = G.expanded_assignments;
                while (*cpp) {
                        char *cp = *cpp;
-                       if (strncmp(cp, name, len) == 0 && cp[len] == '=')
-                               return cp + len + 1;
+                       if (varcmp(cp, name) == 0)
+                               return strchr(cp, '=') + 1;
                        cpp++;
                }
        }
 
-       vpp = get_ptr_to_local_var(name, len);
+       vpp = get_ptr_to_local_var(name);
        if (vpp)
-               return (*vpp)->varstr + len + 1;
+               return strchr((*vpp)->varstr, '=') + 1;
 
 #ifndef __U_BOOT__
        if (strcmp(name, "PPID") == 0)
@@ -2393,13 +2417,11 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
 
 #ifndef __U_BOOT__
 #if ENABLE_HUSH_GETOPTS
-static void handle_changed_special_names(const char *name, unsigned name_len)
+static void handle_changed_special_names(const char *name)
 {
-       if (name_len == 6) {
-               if (strncmp(name, "OPTIND", 6) == 0) {
-                       G.getopt_count = 0;
-                       return;
-               }
+       if (varcmp(name, "OPTIND") == 0) {
+               G.getopt_count = 0;
+               return;
        }
 }
 #else
@@ -2574,16 +2596,21 @@ int set_local_var_modern(char *str, int flags)
 #endif /* !__U_BOOT__ */
        free(free_me);
 
-       handle_changed_special_names(cur->varstr, name_len - 1);
+       handle_changed_special_names(cur->varstr);
 
        return retval;
 }
 
 #ifndef __U_BOOT__
+static int set_local_var0(char *str)
+{
+       return set_local_var(str, 0);
+}
+
 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
 {
        char *var = xasprintf("%s=%s", name, val);
-       set_local_var(var, /*flag:*/ 0);
+       set_local_var0(var);
 }
 
 /* Used at startup and after each cd */
@@ -2594,16 +2621,14 @@ static void set_pwd_var(unsigned flag)
 #endif /* !__U_BOOT__ */
 
 #if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS
-static int unset_local_var_len(const char *name, int name_len)
+static int unset_local_var(const char *name)
 {
        struct variable *cur;
        struct variable **cur_pp;
 
        cur_pp = &G.top_var;
        while ((cur = *cur_pp) != NULL) {
-               if (strncmp(cur->varstr, name, name_len) == 0
-                && cur->varstr[name_len] == '='
-               ) {
+               if (varcmp(cur->varstr, name) == 0) {
                        if (cur->flg_read_only) {
                                bb_error_msg("%s: readonly variable", name);
                                return EXIT_FAILURE;
@@ -2622,15 +2647,10 @@ static int unset_local_var_len(const char *name, int name_len)
        }
 
        /* Handle "unset LINENO" et al even if did not find the variable to unset */
-       handle_changed_special_names(name, name_len);
+       handle_changed_special_names(name);
 
        return EXIT_SUCCESS;
 }
-
-static int unset_local_var(const char *name)
-{
-       return unset_local_var_len(name, strlen(name));
-}
 #endif
 
 
@@ -2677,7 +2697,7 @@ static void set_vars_and_save_old(char **strings)
                eq = strchr(*s, '=');
                if (HUSH_DEBUG && !eq)
                        bb_simple_error_msg_and_die("BUG in varexp4");
-               var_pp = get_ptr_to_local_var(*s, eq - *s);
+               var_pp = get_ptr_to_local_var(*s);
                if (var_pp) {
                        var_p = *var_pp;
                        if (var_p->flg_read_only) {
@@ -2787,30 +2807,54 @@ static void get_user_input(struct in_str *i)
        for (;;) {
                reinit_unicode_for_hush();
                G.flag_SIGINT = 0;
-               /* buglet: SIGINT will not make new prompt to appear _at once_,
-                * only after <Enter>. (^C works immediately) */
-               r = read_line_input(G.line_input_state, prompt_str,
+
+               bb_got_signal = 0;
+               if (!sigisemptyset(&G.pending_set)) {
+                       /* Whoops, already got a signal, do not call read_line_input */
+                       bb_got_signal = r = -1;
+               } else {
+                       /* For shell, LI_INTERRUPTIBLE is set:
+                        * read_line_input will abort on either
+                        * getting EINTR in poll() and bb_got_signal became != 0,
+                        * or if it sees bb_got_signal != 0
+                        * (IOW: if signal arrives before poll() is reached).
+                        * Interactive testcases:
+                        * (while kill -INT $$; do sleep 1; done) &
+                        * #^^^ prints ^C, prints prompt, repeats
+                        * trap 'echo I' int; (while kill -INT $$; do sleep 1; done) &
+                        * #^^^ prints ^C, prints "I", prints prompt, repeats
+                        * trap 'echo T' term; (while kill $$; do sleep 1; done) &
+                        * #^^^ prints "T", prints prompt, repeats
+                        * #(bash 5.0.17 exits after first "T", looks like a bug)
+                        */
+                       r = read_line_input(G.line_input_state, prompt_str,
                                G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
-               );
-               /* read_line_input intercepts ^C, "convert" it to SIGINT */
-               if (r == 0) {
-                       raise(SIGINT);
+                       );
+                       /* read_line_input intercepts ^C, "convert" it to SIGINT */
+                       if (r == 0)
+                               raise(SIGINT);
+               }
+               /* bash prints ^C (before running a trap, if any)
+                * both on keyboard ^C and on real SIGINT (non-kbd generated).
+                */
+               if (sigismember(&G.pending_set, SIGINT)) {
+                       write(STDOUT_FILENO, "^C\n", 3);
+                       G.last_exitcode = 128 | SIGINT;
                }
                check_and_run_traps();
-               if (r != 0 && !G.flag_SIGINT)
+               if (r == 0) /* keyboard ^C? */
+                       continue; /* go back, read another input line */
+               if (r > 0) /* normal input? (no ^C, no ^D, no signals) */
                        break;
-               /* ^C or SIGINT: repeat */
-               /* bash prints ^C even on real SIGINT (non-kbd generated) */
-               write(STDOUT_FILENO, "^C\n", 3);
-               G.last_exitcode = 128 | SIGINT;
-       }
-       if (r < 0) {
-               /* EOF/error detected */
-               /* ^D on interactive input goes to next line before exiting: */
-               write(STDOUT_FILENO, "\n", 1);
-               i->p = NULL;
-               i->peek_buf[0] = r = EOF;
-               return r;
+               if (!bb_got_signal) {
+                       /* r < 0: ^D/EOF/error detected (but not signal) */
+                       /* ^D on interactive input goes to next line before exiting: */
+                       write(STDOUT_FILENO, "\n", 1);
+                       i->p = NULL;
+                       i->peek_buf[0] = r = EOF;
+                       return r;
+               }
+               /* it was a signal: go back, read another input line */
        }
        i->p = G.user_input_buf;
        return (unsigned char)*i->p++;
@@ -2990,6 +3034,12 @@ static int i_getch(struct in_str *i)
                if (ch != '\0') {
                        i->p++;
                        i->last_char = ch;
+#if ENABLE_HUSH_LINENO_VAR
+                       if (ch == '\n') {
+                               G.parse_lineno++;
+                               debug_printf_parse("G.parse_lineno++ = %u\n", G.parse_lineno);
+                       }
+#endif
                        return ch;
                }
                return EOF;
@@ -3637,7 +3687,7 @@ static int glob_brace(char *pattern, o_string *o, int n)
         * NEXT points past the terminator of the first element, and REST
         * points past the final }.  We will accumulate result names from
         * recursive runs for each brace alternative in the buffer using
-        * GLOB_APPEND.  */
+        * GLOB_APPEND. */
 
        p = begin + 1;
        while (1) {
@@ -3953,7 +4003,7 @@ static void free_pipe_list(struct pipe *pi)
 #ifndef debug_print_tree
 static void debug_print_tree(struct pipe *pi, int lvl)
 {
-       static const char *const PIPE[] = {
+       static const char *const PIPE[] ALIGN_PTR = {
                [PIPE_SEQ] = "SEQ",
                [PIPE_AND] = "AND",
                [PIPE_OR ] = "OR" ,
@@ -3988,7 +4038,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
                [RES_XXXX ] = "XXXX" ,
                [RES_SNTX ] = "SNTX" ,
        };
-       static const char *const CMDTYPE[] = {
+       static const char *const CMDTYPE[] ALIGN_PTR = {
                "{}",
                "()",
                "[noglob]",
@@ -4575,7 +4625,7 @@ static int done_word(struct parse_context *ctx)
                 || endofname(command->argv[0])[0] != '\0'
                ) {
                        /* bash says just "not a valid identifier" */
-                       syntax_error("bad variable name in for");
+                       syntax_error("bad for loop variable");
                        return 1;
                }
                /* Force FOR to have just one word (variable name) */
@@ -4966,6 +5016,11 @@ static int parse_group(struct parse_context *ctx,
                        syntax_error_unexpected_ch(ch);
                        return -1;
                }
+//bash allows functions named "123", "..", "return"!
+//             if (endofname(command->argv[0])[0] != '\0') {
+//                     syntax_error("bad function name");
+//                     return -1;
+//             }
                nommu_addchr(&ctx->as_string, ch);
                command->cmd_type = CMD_FUNCDEF;
                goto skip;
@@ -5353,7 +5408,7 @@ static int parse_dollar_squote(o_string *as_string, o_string *dest, struct in_st
 # undef as_string
 }
 #else
-# #define parse_dollar_squote(as_string, dest, input) 0
+# define parse_dollar_squote(as_string, dest, input) 0
 #endif /* BASH_DOLLAR_SQUOTE */
 #endif /* !__U_BOOT__ */
 
@@ -6720,7 +6775,7 @@ static char *encode_then_expand_vararg(const char *str, int handle_squotes, int
 
 /* Expanding ARG in ${var+ARG}, ${var-ARG}
  */
-static int encode_then_append_var_plusminus(o_string *output, int n,
+static NOINLINE int encode_then_append_var_plusminus(o_string *output, int n,
                char *str, int dquoted)
 {
        struct in_str input;
@@ -6753,7 +6808,7 @@ static int encode_then_append_var_plusminus(o_string *output, int n,
                if (!dest.o_expflags) {
                        if (ch == EOF)
                                break;
-                       if (!dquoted && strchr(G.ifs, ch)) {
+                       if (!dquoted && !(output->o_expflags & EXP_FLAG_SINGLEWORD) && strchr(G.ifs, ch)) {
                                /* PREFIX${x:d${e}f ...} and we met space: expand "d${e}f" and start new word.
                                 * do not assume we are at the start of the word (PREFIX above).
                                 */
@@ -6885,16 +6940,21 @@ static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
 /* ${var/[/]pattern[/repl]} helpers */
 static char *strstr_pattern(char *val, const char *pattern, int *size)
 {
-       int sz = strcspn(pattern, "*?[\\");
-       if (pattern[sz] == '\0') {
+       int first_escaped = (pattern[0] == '\\' && pattern[1]);
+       /* "first_escaped" trick allows to treat e.g. "\*no_glob_chars"
+        * as literal too (as it is semi-common, and easy to accomodate
+        * by just using str + 1).
+        */
+       int sz = strcspn(pattern + first_escaped * 2, "*?[\\");
+       if ((pattern + first_escaped * 2)[sz] == '\0') {
                /* Optimization for trivial patterns.
                 * Testcase for very slow replace (performs about 22k replaces):
                 * x=::::::::::::::::::::::
                 * x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;echo ${#x}
                 * echo "${x//:/|}"
                 */
-               *size = sz;
-               return strstr(val, pattern);
+               *size = sz + first_escaped;
+               return strstr(val, pattern + first_escaped);
        }
 
        while (1) {
@@ -7370,7 +7430,7 @@ static NOINLINE int expand_one_var(o_string *output, int n,
                                                        val = NULL;
                                                } else {
                                                        char *new_var = xasprintf("%s=%s", var, val);
-                                                       set_local_var(new_var, /*flag:*/ 0);
+                                                       set_local_var0(new_var);
                                                }
                                        }
                                }
@@ -7858,6 +7918,9 @@ static void re_execute_shell(char ***to_free, const char *s,
                if (!cur->flg_export || cur->flg_read_only)
                        cnt += 2;
        }
+# if ENABLE_HUSH_LINENO_VAR
+       cnt += 2;
+# endif
 # if ENABLE_HUSH_FUNCTIONS
        for (funcp = G.top_func; funcp; funcp = funcp->next)
                cnt += 3;
@@ -7879,6 +7942,10 @@ static void re_execute_shell(char ***to_free, const char *s,
                        *pp++ = cur->varstr;
                }
        }
+# if ENABLE_HUSH_LINENO_VAR
+       *pp++ = (char *) "-L";
+       *pp++ = utoa(G.execute_lineno);
+# endif
 # if ENABLE_HUSH_FUNCTIONS
        for (funcp = G.top_func; funcp; funcp = funcp->next) {
                *pp++ = (char *) "-F";
@@ -8025,7 +8092,11 @@ static int parse_and_run_string(const char *s)
 #endif /* __U_BOOT__ */
 {
        struct in_str input;
+#ifndef __U_BOOT__
+       IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#else /* __U_BOOT__ */
        //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#endif /* __U_BOOT__ */
 
        setup_string_in_str(&input, s);
 #ifndef __U_BOOT__
@@ -8033,7 +8104,11 @@ static int parse_and_run_string(const char *s)
 #else /* __U_BOOT__ */
        return parse_and_run_stream(&input, '\0');
 #endif /* __U_BOOT__ */
-       //IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
+#ifndef __U_BOOT__
+       IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#else /* __U_BOOT__ */
+       //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#endif /* __U_BOOT__ */
 }
 
 #ifdef __U_BOOT__
@@ -8141,7 +8216,7 @@ static int generate_stream_from_string(const char *s, pid_t *pid_p)
                if (is_prefixed_with(s, "trap")
                 && skip_whitespace(s + 4)[0] == '\0'
                ) {
-                       static const char *const argv[] = { NULL, NULL };
+                       static const char *const argv[] ALIGN_PTR = { NULL, NULL };
                        builtin_trap((char**)argv);
                        fflush_all(); /* important */
                        _exit(0);
@@ -8670,8 +8745,8 @@ static const struct built_in_command *find_builtin(const char *name)
        return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
 }
 
-#if ENABLE_HUSH_JOB && EDITING_HAS_get_exe_name
-static const char * FAST_FUNC get_builtin_name(int i)
+#if ENABLE_HUSH_JOB && ENABLE_FEATURE_TAB_COMPLETION
+static const char * FAST_FUNC hush_command_name(int i)
 {
        if (/*i >= 0 && */ i < ARRAY_SIZE(bltins1)) {
                return bltins1[i].b_cmd;
@@ -8680,6 +8755,16 @@ static const char * FAST_FUNC get_builtin_name(int i)
        if (i < ARRAY_SIZE(bltins2)) {
                return bltins2[i].b_cmd;
        }
+# if ENABLE_HUSH_FUNCTIONS
+       {
+               struct function *funcp;
+               i -= ARRAY_SIZE(bltins2);
+               for (funcp = G.top_func; funcp; funcp = funcp->next) {
+                       if (--i < 0)
+                               return funcp->name;
+               }
+       }
+# endif
        return NULL;
 }
 #endif
@@ -9106,7 +9191,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
                 * expand_assignments(): think about ... | var=`sleep 1` | ...
                 */
                free_strings(new_env);
-               _exit(EXIT_SUCCESS);
+               _exit_SUCCESS();
        }
 
        sv_shadowed = G.shadowed_vars_pp;
@@ -9287,7 +9372,7 @@ static void pseudo_exec(nommu_save_t *nommu_save,
 
        /* Case when we are here: ... | >file */
        debug_printf_exec("pseudo_exec'ed null command\n");
-       _exit(EXIT_SUCCESS);
+       _exit_SUCCESS();
 }
 
 #if ENABLE_HUSH_JOB
@@ -9894,7 +9979,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
 #endif
                                debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p);
 #ifndef __U_BOOT__
-                               if (set_local_var(p, /*flag:*/ 0)) {
+                               if (set_local_var0(p)) {
 #else /* __U_BOOT__ */
                                if (set_local_var_modern(p, /*flag:*/ 0)) {
 #endif
@@ -10295,7 +10380,7 @@ static int run_list(struct pipe *pi)
 #endif
 
 #ifndef __U_BOOT__
-       debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
+       debug_printf_exec("run_list lvl %d start\n", G.run_list_level);
        debug_enter();
 #endif /* !__U_BOOT__ */
 
@@ -10361,7 +10446,7 @@ static int run_list(struct pipe *pi)
 #endif /* !__U_BOOT__ */
 
                IF_HAS_KEYWORDS(rword = pi->res_word;)
-               debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
+               debug_printf_exec(": rword:%d cond_code:%d last_rword:%d\n",
                                rword, cond_code, last_rword);
 
                sv_errexit_depth = G.errexit_depth;
@@ -10395,23 +10480,29 @@ static int run_list(struct pipe *pi)
                        }
                }
                last_followup = pi->followup;
-               IF_HAS_KEYWORDS(last_rword = rword;)
 #if ENABLE_HUSH_IF
-               if (cond_code) {
+               if (cond_code != 0) {
                        if (rword == RES_THEN) {
                                /* if false; then ... fi has exitcode 0! */
                                G.last_exitcode = rcode = EXIT_SUCCESS;
                                /* "if <false> THEN cmd": skip cmd */
+                               debug_printf_exec("skipped THEN cmd because IF condition was false\n");
+                               last_rword = rword;
                                continue;
                        }
                } else {
-                       if (rword == RES_ELSE || rword == RES_ELIF) {
+                       if (rword == RES_ELSE
+                        || (rword == RES_ELIF && last_rword != RES_ELIF)
+                       ) {
                                /* "if <true> then ... ELSE/ELIF cmd":
                                 * skip cmd and all following ones */
+                               debug_printf_exec("skipped ELSE/ELIF branch because IF condition was true\n");
                                break;
                        }
+                       //if (rword == RES_THEN): "if <true> THEN cmd", run cmd (fall through)
                }
 #endif
+               IF_HAS_KEYWORDS(last_rword = rword;)
 #if ENABLE_HUSH_LOOPS
                if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
                        if (!for_lcur) {
@@ -10420,7 +10511,7 @@ static int run_list(struct pipe *pi)
                                static const char encoded_dollar_at[] ALIGN1 = {
                                        SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
                                }; /* encoded representation of "$@" */
-                               static const char *const encoded_dollar_at_argv[] = {
+                               static const char *const encoded_dollar_at_argv[] ALIGN_PTR = {
                                        encoded_dollar_at, NULL
                                }; /* argv list with one element: "$@" */
                                char **vals;
@@ -10451,7 +10542,7 @@ static int run_list(struct pipe *pi)
                        /* Insert next value from for_lcur */
                        /* note: *for_lcur already has quotes removed, $var expanded, etc */
 #ifndef __U_BOOT__
-                       set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
+                       set_local_var_from_halves(pi->cmds[0].argv[0], *for_lcur++);
 #else /* __U_BOOT__ */
                        /* We cannot use xasprintf, so we emulate it. */
                        char *full_var;
@@ -10500,7 +10591,7 @@ static int run_list(struct pipe *pi)
                                );
                                /* TODO: which FNM_xxx flags to use? */
                                cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
-                               debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n",
+                               debug_printf_exec("cond_code=fnmatch(pattern:'%s',str:'%s'):%d\n",
                                                pattern, case_word, cond_code);
                                free(pattern);
                                if (cond_code == 0) {
@@ -10547,8 +10638,11 @@ static int run_list(struct pipe *pi)
                G.flag_break_continue = 0;
 #endif
 #endif /* !__U_BOOT__ */
+#ifndef __U_BOOT__
+               rcode = r = G.o_opt[OPT_O_NOEXEC] ? 0 : run_pipe(pi);
+               /* NB: rcode is a smalluint, r is int */
+#else /* __U_BOOT__ */
                rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
-#ifdef __U_BOOT__
                if (r <= EXIT_RET_CODE) {
                        int previous_rcode = G.last_exitcode;
                        /*
@@ -10672,8 +10766,10 @@ static int run_list(struct pipe *pi)
 
                /* Analyze how result affects subsequent commands */
 #if ENABLE_HUSH_IF
-               if (rword == RES_IF || rword == RES_ELIF)
+               if (rword == RES_IF || rword == RES_ELIF) {
+                       debug_printf_exec("cond_code=rcode:%d\n", rcode);
                        cond_code = rcode;
+               }
 #endif
 #ifndef __U_BOOT__
  check_jobs_and_continue:
@@ -10717,7 +10813,7 @@ static int run_list(struct pipe *pi)
 #endif
 #ifndef __U_BOOT__
        debug_leave();
-       debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
+       debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level, rcode);
 #endif /* !__U_BOOT__ */
        return rcode;
 }
@@ -10838,7 +10934,10 @@ static int set_mode(int state, char mode, const char *o_opt)
        int idx;
        switch (mode) {
        case 'n':
-               G.o_opt[OPT_O_NOEXEC] = state;
+               /* set -n has no effect in interactive shell */
+               /* Try: while set -n; do echo $-; done */
+               if (!G_interactive_fd)
+                       G.o_opt[OPT_O_NOEXEC] = state;
                break;
        case 'x':
                IF_HUSH_MODE_X(G_x_mode = state;)
@@ -10895,6 +10994,20 @@ int hush_main(int argc, char **argv)
        INIT_G();
        if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
                G.last_exitcode = EXIT_SUCCESS;
+#if !BB_MMU
+       /* "Big heredoc" support via "sh -< STRING" invocation.
+        * Check it first (do not bother to run the usual init code,
+        * it is not needed for this case).
+        */
+       if (argv[1]
+        && argv[1][0] == '-' && argv[1][1] == '<' /*&& !argv[1][2]*/
+        /*&& argv[2] && !argv[3] - we don't check some conditions */
+       ) {
+               full_write1_str(argv[2]);
+               _exit(0);
+       }
+       G.argv0_for_re_execing = argv[0];
+#endif
 #if ENABLE_HUSH_TRAP
 # if ENABLE_HUSH_FUNCTIONS
        G.return_exitcode = -1;
@@ -10905,13 +11018,10 @@ int hush_main(int argc, char **argv)
 #if ENABLE_HUSH_FAST
        G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
 #endif
-#if !BB_MMU
-       G.argv0_for_re_execing = argv[0];
-#endif
 
        cached_getpid = getpid();   /* for tcsetpgrp() during init */
        G.root_pid = cached_getpid; /* for $PID  (NOMMU can override via -$HEXPID:HEXPPID:...) */
-       G.root_ppid = getppid();    /* for $PPID (NOMMU can override)  */
+       G.root_ppid = getppid();    /* for $PPID (NOMMU can override) */
 
        /* Deal with HUSH_VERSION */
        debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
@@ -11023,7 +11133,10 @@ int hush_main(int argc, char **argv)
                int opt = getopt(argc, argv, "+" /* stop at 1st non-option */
                                "cexinsl"
 #if !BB_MMU
-                               "<:$:R:V:"
+                               "$:R:V:"
+# if ENABLE_HUSH_LINENO_VAR
+                               "L:"
+# endif
 # if ENABLE_HUSH_FUNCTIONS
                                "F:"
 # endif
@@ -11042,6 +11155,29 @@ int hush_main(int argc, char **argv)
                        /* Well, we cannot just declare interactiveness,
                         * we have to have some stuff (ctty, etc) */
                        /* G_interactive_fd++; */
+//There are a few cases where bash -i -c 'SCRIPT'
+//has visible effect (differs from bash -c 'SCRIPT'):
+//it ignores TERM:
+//     bash -i -c 'kill $$; echo ALIVE'
+//     ALIVE
+//it resets SIG_IGNed HUP to SIG_DFL:
+//     trap '' hup; bash -i -c 'kill -hup $$; echo ALIVE'
+//     Hangup   [the message is not printed by bash, it's the shell which started it]
+//is talkative about jobs and exiting:
+//     bash -i -c 'sleep 1 & exit'
+//     [1] 16170
+//     exit
+//includes $ENV file (only if run as "sh"):
+//     echo last >/tmp/ENV; ENV=/tmp/ENV sh -i -c 'echo HERE'
+//     last: cannot open /var/log/wtmp: No such file or directory
+//     HERE
+//(under "bash", it's the opposite: it runs $BASH_ENV file only *without* -i).
+//
+//ash -i -c 'sleep 3; sleep 3', on ^C, drops into a prompt instead of exiting
+//(this may be a bug, bash does not do this).
+//(ash -i -c 'sleep 3' won't show this, the last command gets auto-"exec"ed)
+//
+//None of the above feel like useful features people would rely on.
                        break;
                case 's':
                        G.opt_s = 1;
@@ -11050,9 +11186,6 @@ int hush_main(int argc, char **argv)
                        flags |= OPT_login;
                        break;
 #if !BB_MMU
-               case '<': /* "big heredoc" support */
-                       full_write1_str(optarg);
-                       _exit(0);
                case '$': {
                        unsigned long long empty_trap_mask;
 
@@ -11102,6 +11235,11 @@ int hush_main(int argc, char **argv)
                case 'V':
                        set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
                        break;
+# if ENABLE_HUSH_LINENO_VAR
+               case 'L':
+                       G.parse_lineno = xatou(optarg);
+                       break;
+# endif
 # if ENABLE_HUSH_FUNCTIONS
                case 'F': {
                        struct function *funcp = new_function(optarg);
@@ -11306,8 +11444,11 @@ int hush_main(int argc, char **argv)
 
 # if ENABLE_FEATURE_EDITING
                G.line_input_state = new_line_input_t(FOR_SHELL);
-#  if EDITING_HAS_get_exe_name
-               G.line_input_state->get_exe_name = get_builtin_name;
+#  if ENABLE_FEATURE_TAB_COMPLETION
+               G.line_input_state->get_exe_name = hush_command_name;
+#  endif
+#  if EDITING_HAS_sh_get_var
+               G.line_input_state->sh_get_var = get_local_var_value;
 #  endif
 # endif
 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
@@ -11393,6 +11534,11 @@ static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
        return 0;
 }
 
+static int FAST_FUNC builtin_false(char **argv UNUSED_PARAM)
+{
+       return 1;
+}
+
 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
 static NOINLINE int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
 {
@@ -11443,14 +11589,6 @@ static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
 }
 #endif
 
-static char **skip_dash_dash(char **argv)
-{
-       argv++;
-       if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
-               argv++;
-       return argv;
-}
-
 static int FAST_FUNC builtin_cd(char **argv)
 {
        const char *newdir;
@@ -11733,9 +11871,15 @@ static int FAST_FUNC builtin_umask(char **argv)
 }
 #endif
 
-#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
+#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_READONLY || ENABLE_HUSH_SET || ENABLE_HUSH_TRAP
 static void print_escaped(const char *s)
 {
+//TODO? bash "set" does not quote variables which contain only alnums and "%+,-./:=@_~",
+// (but "export" quotes all variables, even with only these chars).
+// I think quoting strings with %+,=~ looks better
+// (example: "set" printing var== instead of var='=' looks strange)
+// IOW: do not quote "-./:@_": / is used in pathnames, : in PATH, -._ often in file names, @ in emails
+
        if (*s == '\'')
                goto squote;
        do {
@@ -11764,7 +11908,7 @@ static int helper_export_local(char **argv, unsigned flags)
                if (*name_end == '\0') {
                        struct variable *var, **vpp;
 
-                       vpp = get_ptr_to_local_var(name, name_end - name);
+                       vpp = get_ptr_to_local_var(name);
                        var = vpp ? *vpp : NULL;
 
                        if (flags & SETFLAG_UNEXPORT) {
@@ -11866,8 +12010,8 @@ static int FAST_FUNC builtin_export(char **argv)
 
                                if (!p) /* wtf? take next variable */
                                        continue;
-                               /* export var= */
-                               printf("export %.*s", (int)(p - s) + 1, s);
+                               /* "export VAR=" */
+                               printf("%s %.*s", "export", (int)(p - s) + 1, s);
                                print_escaped(p + 1);
                                putchar('\n');
 # endif
@@ -11888,6 +12032,9 @@ static int FAST_FUNC builtin_local(char **argv)
                bb_error_msg("%s: not in a function", argv[0]);
                return EXIT_FAILURE; /* bash compat */
        }
+//TODO? ash and bash support "local -" special form,
+//which saves/restores $- around function call (including async returns, such as ^C)
+//(IOW: it makes "set +/-..." effects local)
        argv++;
        /* Since all builtins run in a nested variable level,
         * need to use level - 1 here. Or else the variable will be removed at once
@@ -11908,8 +12055,15 @@ static int FAST_FUNC builtin_readonly(char **argv)
                struct variable *e;
                for (e = G.top_var; e; e = e->next) {
                        if (e->flg_read_only) {
-//TODO: quote value: readonly VAR='VAL'
-                               printf("readonly %s\n", e->varstr);
+                               const char *s = e->varstr;
+                               const char *p = strchr(s, '=');
+
+                               if (!p) /* wtf? take next variable */
+                                       continue;
+                               /* "readonly VAR=" */
+                               printf("%s %.*s", "readonly", (int)(p - s) + 1, s);
+                               print_escaped(p + 1);
+                               putchar('\n');
                        }
                }
                return EXIT_SUCCESS;
@@ -11987,8 +12141,17 @@ static int FAST_FUNC builtin_set(char **argv)
 
        if (arg == NULL) {
                struct variable *e;
-               for (e = G.top_var; e; e = e->next)
-                       puts(e->varstr);
+               for (e = G.top_var; e; e = e->next) {
+                       const char *s = e->varstr;
+                       const char *p = strchr(s, '=');
+
+                       if (!p) /* wtf? take next variable */
+                               continue;
+                       /* var= */
+                       printf("%.*s", (int)(p - s) + 1, s);
+                       print_escaped(p + 1);
+                       putchar('\n');
+               }
                return EXIT_SUCCESS;
        }
 
@@ -12421,7 +12584,7 @@ static int FAST_FUNC builtin_fg_bg(char **argv)
        /* TODO: bash prints a string representation
         * of job being foregrounded (like "sleep 1 | cat") */
        if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
-               /* Put the job into the foreground.  */
+               /* Put the job into the foreground. */
                tcsetpgrp(G_interactive_fd, pi->pgrp);
        }