Merge branch 'busybox' into merge

14 files changed, 404 insertions, 257 deletions

diff --git a/shell/Config.src b/shell/Config.src
index bc7218fe5..d7623f774 100644
--- a/shell/Config.src
+++ b/shell/Config.src
@@ -99,6 +99,11 @@ config FEATURE_SH_MATH_64
         slightly larger, but will allow computation with very large numbers.
         This is not in POSIX, so do not rely on this in portable code.
 
+config FEATURE_SH_MATH_BASE
+        bool "Support BASE#nnnn literals"
+        default y
+        depends on FEATURE_SH_MATH
+
 config FEATURE_SH_EXTRA_QUIET
         bool "Hide message on interactive shell startup"
         default y
diff --git a/shell/ash_test/ash-misc/export1.right b/shell/ash_test/ash-misc/export1.right
new file mode 100644
index 000000000..56647af8e
--- /dev/null
+++ b/shell/ash_test/ash-misc/export1.right
@@ -0,0 +1 @@
+|\w \\ \ \|
diff --git a/shell/ash_test/ash-misc/export1.tests b/shell/ash_test/ash-misc/export1.tests
new file mode 100755
index 000000000..4ffb40bdc
--- /dev/null
+++ b/shell/ash_test/ash-misc/export1.tests
@@ -0,0 +1,2 @@
+export Z='\w \\ \ \'
+echo "|$Z|"
diff --git a/shell/ash_test/ash-vars/param_expand_default.right b/shell/ash_test/ash-vars/param_expand_default.right
index 3eecd1375..7a42f67e8 100644
--- a/shell/ash_test/ash-vars/param_expand_default.right
+++ b/shell/ash_test/ash-vars/param_expand_default.right
@@ -5,3 +5,5 @@ _aaaa _aaaa _aaaa _aaaa _aaaa
 _ _ _ _word _word
 _ _ _ _ _word
 _fff _fff _fff _fff _fff
+1:1
+0:0
diff --git a/shell/ash_test/ash-vars/param_expand_default.tests b/shell/ash_test/ash-vars/param_expand_default.tests
index 5e42d30e3..dbd3e2218 100755
--- a/shell/ash_test/ash-vars/param_expand_default.tests
+++ b/shell/ash_test/ash-vars/param_expand_default.tests
@@ -1,6 +1,5 @@
 # first try some invalid patterns (do in subshell due to parsing error)
 # (set argv0 to "SHELL" to avoid "/path/to/shell: blah" in error messages)
-# valid in bash and ash (same as $-): "$THIS_SH" -c 'echo ${-}' SHELL
 "$THIS_SH" -c 'echo ${:-}' SHELL
 
 # now some funky ones
@@ -21,3 +20,8 @@ echo _$f _${f-} _${f:-} _${f-word} _${f:-word}
 
 f=fff
 echo _$f _${f-} _${f:-} _${f-word} _${f:-word}
+
+set --
+set -- "${1-}"; echo 1:$#
+set --
+set -- ${1-}; echo 0:$#
diff --git a/shell/hush.c b/shell/hush.c
index b3ae73b9b..4b08232a4 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -466,9 +466,9 @@
 
 #define JOB_STATUS_FORMAT    "[%u] %-22s %.40s\n"
 
-#define _SPECIAL_VARS_STR     "_*@$!?#"
-#define SPECIAL_VARS_STR     ("_*@$!?#" + 1)
-#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
+#define _SPECIAL_VARS_STR     "_*@$!?#-"
+#define SPECIAL_VARS_STR     ("_*@$!?#-" + 1)
+#define NUMERIC_SPECVARS_STR ("_*@$!?#-" + 3)
 #if BASH_PATTERN_SUBST
 /* Support / and // replace ops */
 /* Note that // is stored as \ in "encoded" string representation */
@@ -854,8 +854,7 @@ struct globals {
         /* 'interactive_fd' is a fd# open to ctty, if we have one
          * _AND_ if we decided to act interactively */
         int interactive_fd;
-        const char *PS1;
-        IF_FEATURE_EDITING_FANCY_PROMPT(const char *PS2;)
+        IF_NOT_FEATURE_EDITING_FANCY_PROMPT(char *PS1;)
 # define G_interactive_fd (G.interactive_fd)
 #else
 # define G_interactive_fd 0
@@ -903,6 +902,7 @@ struct globals {
 #else
 # define G_x_mode 0
 #endif
+        char opt_s;
 #if ENABLE_HUSH_INTERACTIVE
         smallint promptmode; /* 0: PS1, 1: PS2 */
 #endif
@@ -968,8 +968,8 @@ struct globals {
         smallint we_have_children;
 #endif
 #if ENABLE_HUSH_LINENO_VAR
-        unsigned lineno;
-        char *lineno_var;
+        unsigned parse_lineno;
+        unsigned execute_lineno;
 #endif
         HFILE *HFILE_list;
         /* Which signals have non-DFL handler (even with no traps set)?
@@ -1009,6 +1009,7 @@ struct globals {
         int debug_indent;
 #endif
         struct sigaction sa;
+        char optstring_buf[sizeof("eixs")];
 #if BASH_EPOCH_VARS
         char epoch_buf[sizeof("%lu.nnnnnn") + sizeof(long)*3];
 #endif
@@ -1448,13 +1449,6 @@ static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
 #endif
 
 
-#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
-static void cmdedit_update_prompt(void);
-#else
-# define cmdedit_update_prompt() ((void)0)
-#endif
-
-
 /* Utility functions
  */
 /* Replace each \x with x in place, return ptr past NUL. */
@@ -2039,7 +2033,8 @@ static sighandler_t pick_sighandler(unsigned sig)
 static void hush_exit(int exitcode)
 {
 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
-        save_history(G.line_input_state);
+        if (G.line_input_state)
+                save_history(G.line_input_state);
 #endif
 
         fflush_all();
@@ -2229,6 +2224,10 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
         if (strcmp(name, "RANDOM") == 0)
                 return utoa(next_random(&G.random_gen));
 #endif
+#if ENABLE_HUSH_LINENO_VAR
+        if (strcmp(name, "LINENO") == 0)
+                return utoa(G.execute_lineno);
+#endif
 #if BASH_EPOCH_VARS
         {
                 const char *fmt = NULL;
@@ -2248,32 +2247,20 @@ static const char* FAST_FUNC get_local_var_value(const char *name)
         return NULL;
 }
 
+#if ENABLE_HUSH_GETOPTS
 static void handle_changed_special_names(const char *name, unsigned name_len)
 {
-        if (ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
-         && name_len == 3 && name[0] == 'P' && name[1] == 'S'
-        ) {
-                cmdedit_update_prompt();
-                return;
-        }
-
-        if ((ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS)
-         && name_len == 6
-        ) {
-#if ENABLE_HUSH_LINENO_VAR
-                if (strncmp(name, "LINENO", 6) == 0) {
-                        G.lineno_var = NULL;
-                        return;
-                }
-#endif
-#if ENABLE_HUSH_GETOPTS
+        if (name_len == 6) {
                 if (strncmp(name, "OPTIND", 6) == 0) {
                         G.getopt_count = 0;
                         return;
                 }
-#endif
         }
 }
+#else
+/* Do not even bother evaluating arguments */
+# define handle_changed_special_names(...) ((void)0)
+#endif
 
 /* str holds "NAME=VAL" and is expected to be malloced.
  * We take ownership of it.
@@ -2289,6 +2276,7 @@ static int set_local_var(char *str, unsigned flags)
         char *free_me = NULL;
         char *eq_sign;
         int name_len;
+        int retval;
         unsigned local_lvl = (flags >> SETFLAG_VARLVL_SHIFT);
 
         eq_sign = strchr(str, '=');
@@ -2402,24 +2390,24 @@ static int set_local_var(char *str, unsigned flags)
 #endif
         if (flags & SETFLAG_EXPORT)
                 cur->flg_export = 1;
+        retval = 0;
         if (cur->flg_export) {
                 if (flags & SETFLAG_UNEXPORT) {
                         cur->flg_export = 0;
                         /* unsetenv was already done */
                 } else {
-                        int i;
                         debug_printf_env("%s: putenv '%s'/%u\n", __func__, cur->varstr, cur->var_nest_level);
-                        i = putenv(cur->varstr);
-                        /* only now we can free old exported malloced string */
-                        free(free_me);
-                        return i;
+                        retval = putenv(cur->varstr);
+                        /* fall through to "free(free_me)" -
+                         * only now we can free old exported malloced string
+                         */
                 }
         }
         free(free_me);
 
         handle_changed_special_names(cur->varstr, name_len - 1);
 
-        return 0;
+        return retval;
 }
 
 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
@@ -2462,7 +2450,7 @@ static int unset_local_var_len(const char *name, int name_len)
                 cur_pp = &cur->next;
         }
 
-        /* Handle "unset PS1" et al even if did not find the variable to unset */
+        /* Handle "unset LINENO" et al even if did not find the variable to unset */
         handle_changed_special_names(name, name_len);
 
         return EXIT_SUCCESS;
@@ -2581,36 +2569,27 @@ static void reinit_unicode_for_hush(void)
  *      \
  * It exercises a lot of corner cases.
  */
-# if ENABLE_FEATURE_EDITING_FANCY_PROMPT
-static void cmdedit_update_prompt(void)
-{
-        G.PS1 = get_local_var_value("PS1");
-        if (G.PS1 == NULL)
-                G.PS1 = "";
-        G.PS2 = get_local_var_value("PS2");
-        if (G.PS2 == NULL)
-                G.PS2 = "";
-}
-# endif
 static const char *setup_prompt_string(void)
 {
         const char *prompt_str;
 
         debug_printf_prompt("%s promptmode:%d\n", __func__, G.promptmode);
 
-        IF_FEATURE_EDITING_FANCY_PROMPT(    prompt_str = G.PS2;)
-        IF_NOT_FEATURE_EDITING_FANCY_PROMPT(prompt_str = "> ";)
+# if ENABLE_FEATURE_EDITING_FANCY_PROMPT
+        prompt_str = get_local_var_value(G.promptmode == 0 ? "PS1" : "PS2");
+        if (!prompt_str)
+                prompt_str = "";
+# else
+        prompt_str = "> "; /* if PS2, else... */
         if (G.promptmode == 0) { /* PS1 */
-                if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
-                        /* No fancy prompts supported, (re)generate "CURDIR $ " by hand */
-                        free((char*)G.PS1);
-                        /* bash uses $PWD value, even if it is set by user.
-                         * It uses current dir only if PWD is unset.
-                         * We always use current dir. */
-                        G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
-                }
-                prompt_str = G.PS1;
+                /* No fancy prompts supported, (re)generate "CURDIR $ " by hand */
+                free(G.PS1);
+                /* bash uses $PWD value, even if it is set by user.
+                 * It uses current dir only if PWD is unset.
+                 * We always use current dir. */
+                G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
         }
+# endif
         debug_printf("prompt_str '%s'\n", prompt_str);
         return prompt_str;
 }
@@ -2747,8 +2726,8 @@ static int i_getch(struct in_str *i)
         i->last_char = ch;
 #if ENABLE_HUSH_LINENO_VAR
         if (ch == '\n') {
-                G.lineno++;
-                debug_printf_parse("G.lineno++ = %u\n", G.lineno);
+                G.parse_lineno++;
+                debug_printf_parse("G.parse_lineno++ = %u\n", G.parse_lineno);
         }
 #endif
         return ch;
@@ -3750,8 +3729,8 @@ static int done_command(struct parse_context *ctx)
  clear_and_ret:
         memset(command, 0, sizeof(*command));
 #if ENABLE_HUSH_LINENO_VAR
-        command->lineno = G.lineno;
-        debug_printf_parse("command->lineno = G.lineno (%u)\n", G.lineno);
+        command->lineno = G.parse_lineno;
+        debug_printf_parse("command->lineno = G.parse_lineno (%u)\n", G.parse_lineno);
 #endif
         return pi->num_cmds; /* used only for 0/nonzero check */
 }
@@ -4198,7 +4177,7 @@ static int done_word(struct parse_context *ctx)
 #if ENABLE_HUSH_LOOPS
         if (ctx->ctx_res_w == RES_FOR) {
                 if (ctx->word.has_quoted_part
-                 || !is_well_formed_var_name(command->argv[0], '\0')
+                 || endofname(command->argv[0])[0] != '\0'
                 ) {
                         /* bash says just "not a valid identifier" */
                         syntax_error("not a valid identifier in for");
@@ -4912,6 +4891,7 @@ static int parse_dollar(o_string *as_string,
         case '#': /* number of args */
         case '*': /* args */
         case '@': /* args */
+        case '-': /* $- option flags set by set builtin or shell options (-i etc) */
                 goto make_one_char_var;
         case '{': {
                 char len_single_ch;
@@ -5086,11 +5066,10 @@ static int parse_dollar(o_string *as_string,
         case '_':
                 goto make_var;
 #if 0
-        /* TODO: $_ and $-: */
+        /* TODO: $_: */
         /* $_ Shell or shell script name; or last argument of last command
          * (if last command wasn't a pipe; if it was, bash sets $_ to "");
          * but in command's env, set to full pathname used to invoke it */
-        /* $- Option flags set by set builtin or shell options (-i etc) */
                 ch = i_getch(input);
                 nommu_addchr(as_string, ch);
                 ch = i_peek_and_eat_bkslash_nl(input);
@@ -5372,7 +5351,7 @@ static struct pipe *parse_stream(char **pstring,
                         if ((ctx.is_assignment == MAYBE_ASSIGNMENT
                             || ctx.is_assignment == WORD_IS_KEYWORD)
                          && ch == '='
-                         && is_well_formed_var_name(ctx.word.data, '=')
+                         && endofname(ctx.word.data)[0] == '='
                         ) {
                                 ctx.is_assignment = DEFINITELY_ASSIGNMENT;
                                 debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
@@ -6119,6 +6098,12 @@ static int encode_then_append_var_plusminus(o_string *output, int n,
                 /* string has no special chars
                  * && string has no $IFS chars
                  */
+                if (dquoted) {
+                        /* Prints 1 (quoted expansion is a "" word, not nothing):
+                         * set -- "${notexist-}"; echo $#
+                         */
+                        output->has_quoted_part = 1;
+                }
                 return expand_vars_to_list(output, n, str);
         }
 
@@ -6415,6 +6400,26 @@ static NOINLINE int expand_one_var(o_string *output, int n,
                 case '#': /* argc */
                         val = utoa(G.global_argc ? G.global_argc-1 : 0);
                         break;
+                case '-': { /* active options */
+                        /* Check set_mode() to see what option chars we support */
+                        char *cp;
+                        val = cp = G.optstring_buf;
+                        if (G.o_opt[OPT_O_ERREXIT])
+                                *cp++ = 'e';
+                        if (G_interactive_fd)
+                                *cp++ = 'i';
+                        if (G_x_mode)
+                                *cp++ = 'x';
+                        /* If G.o_opt[OPT_O_NOEXEC] is true,
+                         * commands read but are not executed,
+                         * so $- can not execute too, 'n' is never seen in $-.
+                         */
+                        if (G.opt_s)
+                                *cp++ = 's';
+//TODO: show 'c' if executed via "hush -c 'CMDS'" (bash only, not ash)
+                        *cp = '\0';
+                        break;
+                }
                 default:
                         val = get_local_var_value(var);
                 }
@@ -7275,22 +7280,22 @@ static void parse_and_run_stream(struct in_str *inp, int end_trigger)
 static void parse_and_run_string(const char *s)
 {
         struct in_str input;
-        //IF_HUSH_LINENO_VAR(unsigned sv = G.lineno;)
+        //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
 
         setup_string_in_str(&input, s);
         parse_and_run_stream(&input, '\0');
-        //IF_HUSH_LINENO_VAR(G.lineno = sv;)
+        //IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
 }
 
 static void parse_and_run_file(HFILE *fp)
 {
         struct in_str input;
-        IF_HUSH_LINENO_VAR(unsigned sv = G.lineno;)
+        IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
 
-        IF_HUSH_LINENO_VAR(G.lineno = 1;)
+        IF_HUSH_LINENO_VAR(G.parse_lineno = 1;)
         setup_file_in_str(&input, fp);
         parse_and_run_stream(&input, ';');
-        IF_HUSH_LINENO_VAR(G.lineno = sv;)
+        IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
 }
 
 #if ENABLE_HUSH_TICK
@@ -7598,10 +7603,10 @@ static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
                 avoid_fd = 9;
 
 #if ENABLE_HUSH_INTERACTIVE
-        if (fd == G.interactive_fd) {
+        if (fd == G_interactive_fd) {
                 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
-                G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
-                debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
+                G_interactive_fd = xdup_CLOEXEC_and_close(G_interactive_fd, avoid_fd);
+                debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G_interactive_fd);
                 return 1; /* "we closed fd" */
         }
 #endif
@@ -7677,7 +7682,7 @@ static void restore_redirects(struct squirrel *sq)
                 free(sq);
         }
 
-        /* If moved, G.interactive_fd stays on new fd, not restoring it */
+        /* If moved, G_interactive_fd stays on new fd, not restoring it */
 }
 
 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
@@ -7694,7 +7699,7 @@ static int internally_opened_fd(int fd, struct squirrel *sq)
         int i;
 
 #if ENABLE_HUSH_INTERACTIVE
-        if (fd == G.interactive_fd)
+        if (fd == G_interactive_fd)
                 return 1;
 #endif
         /* If this one of script's fds? */
@@ -8989,8 +8994,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
                 struct variable *old_vars;
 
 #if ENABLE_HUSH_LINENO_VAR
-                if (G.lineno_var)
-                        strcpy(G.lineno_var + sizeof("LINENO=")-1, utoa(command->lineno));
+                G.execute_lineno = command->lineno;
 #endif
 
                 if (argv[command->assignment_cnt] == NULL) {
@@ -9223,8 +9227,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         xpiped_pair(pipefds);
 
 #if ENABLE_HUSH_LINENO_VAR
-                if (G.lineno_var)
-                        strcpy(G.lineno_var + sizeof("LINENO=")-1, utoa(command->lineno));
+                G.execute_lineno = command->lineno;
 #endif
 
                 command->pid = BB_MMU ? fork() : vfork();
@@ -9908,14 +9911,6 @@ int hush_main(int argc, char **argv)
         /* Export PWD */
         set_pwd_var(SETFLAG_EXPORT);
 
-#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
-        /* Set (but not export) PS1/2 unless already set */
-        if (!get_local_var_value("PS1"))
-                set_local_var_from_halves("PS1", "\\w \\$ ");
-        if (!get_local_var_value("PS2"))
-                set_local_var_from_halves("PS2", "> ");
-#endif
-
 #if BASH_HOSTNAME_VAR
         /* Set (but not export) HOSTNAME unless already set */
         if (!get_local_var_value("HOSTNAME")) {
@@ -9927,6 +9922,11 @@ int hush_main(int argc, char **argv)
         /* IFS is not inherited from the parent environment */
         set_local_var_from_halves("IFS", defifs);
 
+        if (!get_local_var_value("PATH"))
+                set_local_var_from_halves("PATH", bb_default_root_path);
+
+        /* PS1/PS2 are set later, if we determine that we are interactive */
+
         /* bash also exports SHLVL and _,
          * and sets (but doesn't export) the following variables:
          * BASH=/bin/bash
@@ -9960,21 +9960,7 @@ int hush_main(int argc, char **argv)
          * PS4='+ '
          */
 
-#if ENABLE_HUSH_LINENO_VAR
-        if (ENABLE_HUSH_LINENO_VAR) {
-                char *p = xasprintf("LINENO=%*s", (int)(sizeof(int)*3), "");
-                set_local_var(p, /*flags*/ 0);
-                G.lineno_var = p; /* can't assign before set_local_var("LINENO=...") */
-        }
-#endif
-
-#if ENABLE_FEATURE_EDITING
-        G.line_input_state = new_line_input_t(FOR_SHELL);
-#endif
-
         /* Initialize some more globals to non-zero values */
-        cmdedit_update_prompt();
-
         die_func = restore_ttypgrp_and__exit;
 
         /* Shell is non-interactive at first. We need to call
@@ -10192,6 +10178,7 @@ int hush_main(int argc, char **argv)
 #endif
                 goto final_return;
         }
+        G.opt_s = 1;
 
         /* Up to here, shell was non-interactive. Now it may become one.
          * NB: don't forget to (re)run install_special_sighandlers() as needed.
@@ -10260,6 +10247,9 @@ int hush_main(int argc, char **argv)
                 }
                 enable_restore_tty_pgrp_on_exit();
 
+# if ENABLE_FEATURE_EDITING
+                G.line_input_state = new_line_input_t(FOR_SHELL);
+# endif
 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
                 {
                         const char *hp = get_local_var_value("HISTFILE");
@@ -10308,14 +10298,23 @@ int hush_main(int argc, char **argv)
          * (--norc turns this off, --rcfile <file> overrides)
          */
 
-        if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
-                /* note: ash and hush share this string */
-                printf("\n\n%s %s\n"
-                        IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
-                        "\n",
-                        bb_banner,
-                        "hush - the humble shell"
-                );
+        if (G_interactive_fd) {
+#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
+                /* Set (but not export) PS1/2 unless already set */
+                if (!get_local_var_value("PS1"))
+                        set_local_var_from_halves("PS1", "\\w \\$ ");
+                if (!get_local_var_value("PS2"))
+                        set_local_var_from_halves("PS2", "> ");
+#endif
+                if (!ENABLE_FEATURE_SH_EXTRA_QUIET) {
+                        /* note: ash and hush share this string */
+                        printf("\n\n%s %s\n"
+                                IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
+                                "\n",
+                                bb_banner,
+                                "hush - the humble shell"
+                        );
+                }
         }
 
         parse_and_run_file(hfopen(NULL)); /* stdin */
@@ -10378,7 +10377,8 @@ static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
 {
-        show_history(G.line_input_state);
+        if (G.line_input_state)
+                show_history(G.line_input_state);
         return EXIT_SUCCESS;
 }
 #endif
@@ -10687,9 +10687,7 @@ static int helper_export_local(char **argv, unsigned flags)
 {
         do {
                 char *name = *argv;
-                char *name_end = strchrnul(name, '=');
-
-                /* So far we do not check that name is valid (TODO?) */
+                const char *name_end = endofname(name);
 
                 if (*name_end == '\0') {
                         struct variable *var, **vpp;
@@ -10747,8 +10745,15 @@ static int helper_export_local(char **argv, unsigned flags)
                          */
                         name = xasprintf("%s=", name);
                 } else {
+                        if (*name_end != '=') {
+                                bb_error_msg("'%s': bad variable name", name);
+                                /* do not parse following argv[]s: */
+                                return 1;
+                        }
                         /* (Un)exporting/making local NAME=VALUE */
                         name = xstrdup(name);
+                        /* Testcase: export PS1='\w \$ ' */
+                        unbackslash(name);
                 }
                 debug_printf_env("%s: set_local_var('%s')\n", __func__, name);
                 if (set_local_var(name, flags))
diff --git a/shell/hush_test/hush-misc/export1.right b/shell/hush_test/hush-misc/export1.right
new file mode 100644
index 000000000..56647af8e
--- /dev/null
+++ b/shell/hush_test/hush-misc/export1.right
@@ -0,0 +1 @@
+|\w \\ \ \|
diff --git a/shell/hush_test/hush-misc/export1.tests b/shell/hush_test/hush-misc/export1.tests
new file mode 100755
index 000000000..4ffb40bdc
--- /dev/null
+++ b/shell/hush_test/hush-misc/export1.tests
@@ -0,0 +1,2 @@
+export Z='\w \\ \ \'
+echo "|$Z|"
diff --git a/shell/hush_test/hush-vars/param_expand_default.right b/shell/hush_test/hush-vars/param_expand_default.right
index acc717205..8bd0814b0 100644
--- a/shell/hush_test/hush-vars/param_expand_default.right
+++ b/shell/hush_test/hush-vars/param_expand_default.right
@@ -1,8 +1,9 @@
 hush: syntax error: unterminated ${name}
-hush: syntax error: unterminated ${name}
 _0 _0
 _ _ _ _word _word
 _aaaa _aaaa _aaaa _aaaa _aaaa
 _ _ _ _word _word
 _ _ _ _ _word
 _fff _fff _fff _fff _fff
+1:1
+0:0
diff --git a/shell/hush_test/hush-vars/param_expand_default.tests b/shell/hush_test/hush-vars/param_expand_default.tests
index 16e5f8efe..dbd3e2218 100755
--- a/shell/hush_test/hush-vars/param_expand_default.tests
+++ b/shell/hush_test/hush-vars/param_expand_default.tests
@@ -1,7 +1,5 @@
 # first try some invalid patterns (do in subshell due to parsing error)
 # (set argv0 to "SHELL" to avoid "/path/to/shell: blah" in error messages)
-# valid in bash and ash (same as $-), not supported in hush (yet?):
-"$THIS_SH" -c 'echo ${-}' SHELL
 "$THIS_SH" -c 'echo ${:-}' SHELL
 
 # now some funky ones
@@ -22,3 +20,8 @@ echo _$f _${f-} _${f:-} _${f-word} _${f:-word}
 
 f=fff
 echo _$f _${f-} _${f:-} _${f-word} _${f:-word}
+
+set --
+set -- "${1-}"; echo 1:$#
+set --
+set -- ${1-}; echo 0:$#
diff --git a/shell/math.c b/shell/math.c
index 611b3beab..eaf4f2453 100644
--- a/shell/math.c
+++ b/shell/math.c
@@ -513,6 +513,46 @@ static const char op_tokens[] ALIGN1 = {
 };
 #define ptr_to_rparen (&op_tokens[sizeof(op_tokens)-7])
 
+#if ENABLE_FEATURE_SH_MATH_BASE
+static arith_t strto_arith_t(const char *nptr, char **endptr)
+{
+        unsigned base;
+        arith_t n;
+
+# if ENABLE_FEATURE_SH_MATH_64
+        n = strtoull(nptr, endptr, 0);
+# else
+        n = strtoul(nptr, endptr, 0);
+# endif
+        if (**endptr != '#'
+         || (*nptr < '1' || *nptr > '9')
+         || (n < 2 || n > 64)
+        ) {
+                return n;
+        }
+
+        /* It's "N#nnnn" or "NN#nnnn" syntax, NN can't start with 0,
+         * NN is in 2..64 range.
+         */
+        base = (unsigned)n;
+        n = 0;
+        nptr = *endptr + 1;
+        /* bash allows "N#" (empty "nnnn" part) */
+        while (isdigit(*nptr)) {
+                /* bash does not check for overflows */
+                n = n * base + (*nptr++ - '0');
+        }
+        *endptr = (char*)nptr;
+        return n;
+}
+#else /* !ENABLE_FEATURE_SH_MATH_BASE */
+# if ENABLE_FEATURE_SH_MATH_64
+#  define strto_arith_t(nptr, endptr) strtoull(nptr, endptr, 0)
+# else
+#  define strto_arith_t(nptr, endptr) strtoul(nptr, endptr, 0)
+# endif
+#endif
+
 static arith_t FAST_FUNC
 evaluate_string(arith_state_t *math_state, const char *expr)
 {
@@ -591,7 +631,7 @@ evaluate_string(arith_state_t *math_state, const char *expr)
                         /* Number */
                         numstackptr->var = NULL;
                         errno = 0;
-                        numstackptr->val = strto_arith_t(expr, (char**) &expr, 0);
+                        numstackptr->val = strto_arith_t(expr, (char**) &expr);
                         if (errno)
                                 numstackptr->val = 0; /* bash compat */
                         goto num;
diff --git a/shell/math.h b/shell/math.h
index 90eb49144..a3fe51b6b 100644
--- a/shell/math.h
+++ b/shell/math.h
@@ -66,11 +66,9 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 #if ENABLE_FEATURE_SH_MATH_64
 typedef long long arith_t;
 #define ARITH_FMT "%"LL_FMT"d"
-#define strto_arith_t strtoull
 #else
 typedef long arith_t;
-#define ARITH_FMT "%ld"
-#define strto_arith_t strtoul
+# define ARITH_FMT "%ld"
 #endif
 
 typedef const char* FAST_FUNC (*arith_var_lookup_t)(const char *name);
diff --git a/shell/shell_common.c b/shell/shell_common.c
index 70ecf2095..d1df5888c 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -26,19 +26,6 @@ const char defifsvar[] ALIGN1 = "IFS= \t\n\r";
 #endif
 const char defoptindvar[] ALIGN1 = "OPTIND=1";
 
-
-int FAST_FUNC is_well_formed_var_name(const char *s, char terminator)
-{
-        if (!s || !(isalpha(*s) || *s == '_'))
-                return 0;
-
-        do
-                s++;
-        while (isalnum(*s) || *s == '_');
-
-        return *s == terminator;
-}
-
 /* read builtin */
 
 /* Needs to be interruptible: shell must handle traps and shell-special signals
@@ -76,7 +63,7 @@ shell_builtin_read(struct builtin_read_params *params)
         argv = params->argv;
         pp = argv;
         while (*pp) {
-                if (!is_well_formed_var_name(*pp, '\0')) {
+                if (endofname(*pp)[0] != '\0') {
                         /* Mimic bash message */
                         bb_error_msg("read: '%s': not a valid identifier", *pp);
                         return (const char *)(uintptr_t)1;
@@ -384,99 +371,138 @@ shell_builtin_read(struct builtin_read_params *params)
 struct limits {
         uint8_t cmd;            /* RLIMIT_xxx fit into it */
         uint8_t factor_shift;   /* shift by to get rlim_{cur,max} values */
-        char option;
         const char *name;
 };
 
 static const struct limits limits_tbl[] = {
-#ifdef RLIMIT_FSIZE
-        { RLIMIT_FSIZE,         9,      'f',    "file size (blocks)" },
+        { RLIMIT_CORE,          9,      "core file size (blocks)" }, // -c
+        { RLIMIT_DATA,          10,     "data seg size (kb)" },      // -d
+        { RLIMIT_NICE,          0,      "scheduling priority" },     // -e
+        { RLIMIT_FSIZE,         9,      "file size (blocks)" },      // -f
+#define LIMIT_F_IDX     3
+#ifdef RLIMIT_SIGPENDING
+        { RLIMIT_SIGPENDING,    0,      "pending signals" },         // -i
 #endif
-#ifdef RLIMIT_CPU
-        { RLIMIT_CPU,           0,      't',    "cpu time (seconds)" },
+#ifdef RLIMIT_MEMLOCK
+        { RLIMIT_MEMLOCK,       10,     "max locked memory (kb)" },  // -l
 #endif
-#ifdef RLIMIT_DATA
-        { RLIMIT_DATA,          10,     'd',    "data seg size (kb)" },
+#ifdef RLIMIT_RSS
+        { RLIMIT_RSS,           10,     "max memory size (kb)" },    // -m
 #endif
-#ifdef RLIMIT_STACK
-        { RLIMIT_STACK,         10,     's',    "stack size (kb)" },
+#ifdef RLIMIT_NOFILE
+        { RLIMIT_NOFILE,        0,      "open files" },              // -n
 #endif
-#ifdef RLIMIT_CORE
-        { RLIMIT_CORE,          9,      'c',    "core file size (blocks)" },
+#ifdef RLIMIT_MSGQUEUE
+        { RLIMIT_MSGQUEUE,      0,      "POSIX message queues (bytes)" }, // -q
 #endif
-#ifdef RLIMIT_RSS
-        { RLIMIT_RSS,           10,     'm',    "resident set size (kb)" },
+#ifdef RLIMIT_RTPRIO
+        { RLIMIT_RTPRIO,        0,      "real-time priority" },      // -r
 #endif
-#ifdef RLIMIT_MEMLOCK
-        { RLIMIT_MEMLOCK,       10,     'l',    "locked memory (kb)" },
+#ifdef RLIMIT_STACK
+        { RLIMIT_STACK,         10,     "stack size (kb)" },         // -s
 #endif
-#ifdef RLIMIT_NPROC
-        { RLIMIT_NPROC,         0,      'p',    "processes" },
+#ifdef RLIMIT_CPU
+        { RLIMIT_CPU,           0,      "cpu time (seconds)" },      // -t
 #endif
-#ifdef RLIMIT_NOFILE
-        { RLIMIT_NOFILE,        0,      'n',    "file descriptors" },
+#ifdef RLIMIT_NPROC
+        { RLIMIT_NPROC,         0,      "max user processes" },      // -u
 #endif
 #ifdef RLIMIT_AS
-        { RLIMIT_AS,            10,     'v',    "address space (kb)" },
+        { RLIMIT_AS,            10,     "virtual memory (kb)" },     // -v
 #endif
 #ifdef RLIMIT_LOCKS
-        { RLIMIT_LOCKS,         0,      'w',    "locks" },
+        { RLIMIT_LOCKS,         0,      "file locks" },              // -x
+#endif
+};
+// bash also shows:
+//pipe size            (512 bytes, -p) 8
+
+static const char limit_chars[] ALIGN1 =
+                        "c"
+                        "d"
+                        "e"
+                        "f"
+#ifdef RLIMIT_SIGPENDING
+                        "i"
+#endif
+#ifdef RLIMIT_MEMLOCK
+                        "l"
+#endif
+#ifdef RLIMIT_RSS
+                        "m"
+#endif
+#ifdef RLIMIT_NOFILE
+                        "n"
 #endif
-#ifdef RLIMIT_NICE
-        { RLIMIT_NICE,          0,      'e',    "scheduling priority" },
+#ifdef RLIMIT_MSGQUEUE
+                        "q"
 #endif
 #ifdef RLIMIT_RTPRIO
-        { RLIMIT_RTPRIO,        0,      'r',    "real-time priority" },
+                        "r"
 #endif
-};
-
-enum {
-        OPT_hard = (1 << 0),
-        OPT_soft = (1 << 1),
-};
-
-/* "-": treat args as parameters of option with ASCII code 1 */
-static const char ulimit_opt_string[] ALIGN1 = "-HSa"
-#ifdef RLIMIT_FSIZE
-                        "f::"
+#ifdef RLIMIT_STACK
+                        "s"
 #endif
 #ifdef RLIMIT_CPU
-                        "t::"
+                        "t"
 #endif
-#ifdef RLIMIT_DATA
-                        "d::"
+#ifdef RLIMIT_NPROC
+                        "u"
 #endif
-#ifdef RLIMIT_STACK
-                        "s::"
+#ifdef RLIMIT_AS
+                        "v"
 #endif
-#ifdef RLIMIT_CORE
-                        "c::"
+#ifdef RLIMIT_LOCKS
+                        "x"
 #endif
-#ifdef RLIMIT_RSS
-                        "m::"
+;
+
+/* "-": treat args as parameters of option with ASCII code 1 */
+static const char ulimit_opt_string[] ALIGN1 = "-HSa"
+                        "c::"
+                        "d::"
+                        "e::"
+                        "f::"
+#ifdef RLIMIT_SIGPENDING
+                        "i::"
 #endif
 #ifdef RLIMIT_MEMLOCK
                         "l::"
 #endif
-#ifdef RLIMIT_NPROC
-                        "p::"
+#ifdef RLIMIT_RSS
+                        "m::"
 #endif
 #ifdef RLIMIT_NOFILE
                         "n::"
 #endif
+#ifdef RLIMIT_MSGQUEUE
+                        "q::"
+#endif
+#ifdef RLIMIT_RTPRIO
+                        "r::"
+#endif
+#ifdef RLIMIT_STACK
+                        "s::"
+#endif
+#ifdef RLIMIT_CPU
+                        "t::"
+#endif
+#ifdef RLIMIT_NPROC
+                        "u::"
+#endif
 #ifdef RLIMIT_AS
                         "v::"
 #endif
 #ifdef RLIMIT_LOCKS
-                        "w::"
-#endif
-#ifdef RLIMIT_NICE
-                        "e::"
-#endif
-#ifdef RLIMIT_RTPRIO
-                        "r::"
+                        "x::"
 #endif
-                        ;
+;
+
+enum {
+        OPT_hard = (1 << 0),
+        OPT_soft = (1 << 1),
+        OPT_all  = (1 << 2),
+};
 
 static void printlim(unsigned opts, const struct rlimit *limit,
                         const struct limits *l)
@@ -484,7 +510,7 @@ static void printlim(unsigned opts, const struct rlimit *limit,
         rlim_t val;
 
         val = limit->rlim_max;
-        if (!(opts & OPT_hard))
+        if (opts & OPT_soft)
                 val = limit->rlim_cur;
 
         if (val == RLIM_INFINITY)
@@ -498,8 +524,11 @@ static void printlim(unsigned opts, const struct rlimit *limit,
 int FAST_FUNC
 shell_builtin_ulimit(char **argv)
 {
+        struct rlimit limit;
+        unsigned opt_cnt;
         unsigned opts;
         unsigned argc;
+        unsigned i;
 
         /* We can't use getopt32: need to handle commands like
          * ulimit 123 -c2 -l 456
@@ -510,12 +539,48 @@ shell_builtin_ulimit(char **argv)
          */
         GETOPT_RESET();
 
+// bash 4.4.23:
+//
+// -H and/or -S change meaning even of options *before* them: ulimit -f 2000 -H
+// sets hard limit, ulimit -a -H prints hard limits.
+//
+// -a is equivalent for requesting all limits to be shown.
+//
+// If -a is specified, attempts to set limits are ignored:
+//  ulimit -m 1000; ulimit -m 2000 -a
+// shows 1000, not 2000. HOWEVER, *implicit* -f form "ulimit 2000 -a"
+// DOES set -f limit [we don't implement this quirk], "ulimit -a 2000" does not.
+// Options are still parsed: ulimit -az complains about unknown -z opt.
+//
+// -a is not cumulative: "ulimit -a -a" = "ulimit -a -f -m" = "ulimit -a"
+//
+// -HSa can be combined in one argument and with one other option (example: -Sm),
+// but other options can't: limit value is an optional argument,
+// thus "-mf" means "-m f", f is the parameter of -m.
+//
+// Limit can be set and then printed: ulimit -m 2000 -m
+// If set more than once, they are set and printed in order:
+// try ulimit -m -m 1000 -m -m 2000 -m -m 3000 -m
+//
+// Limits are shown in the order of options given:
+// ulimit -m -f is not the same as ulimit -f -m.
+//
+// If both -S and -H are given, show soft limit.
+//
+// Short printout (limit value only) is printed only if just one option
+// is given: ulimit -m. ulimit -f -m prints verbose lines.
+// ulimit -f -f prints same verbose line twice.
+// ulimit -m 10000 -f prints verbose line for -f.
+
         argc = string_array_len(argv);
 
+        /* First pass over options: detect -H/-S/-a status,
+         * and "bare ulimit" and "only one option" cases
+         * by counting other opts.
+         */
+        opt_cnt = 0;
         opts = 0;
         while (1) {
-                struct rlimit limit;
-                const struct limits *l;
                 int opt_char = getopt(argc, argv, ulimit_opt_string);
 
                 if (opt_char == -1)
@@ -528,74 +593,94 @@ shell_builtin_ulimit(char **argv)
                         opts |= OPT_soft;
                         continue;
                 }
-
                 if (opt_char == 'a') {
-                        for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
-                                getrlimit(l->cmd, &limit);
-                                printf("-%c: %-30s ", l->option, l->name);
-                                printlim(opts, &limit, l);
-                        }
+                        opts |= OPT_all;
                         continue;
                 }
+                if (opt_char == '?') {
+                        /* bad option. getopt already complained. */
+                        return EXIT_FAILURE;
+                }
+                opt_cnt++;
+        } /* while (there are options) */
+
+        if (!(opts & (OPT_hard | OPT_soft)))
+                opts |= (OPT_hard | OPT_soft);
+        if (opts & OPT_all) {
+                for (i = 0; i < ARRAY_SIZE(limits_tbl); i++) {
+                        getrlimit(limits_tbl[i].cmd, &limit);
+                        printf("%-32s(-%c) ", limits_tbl[i].name, limit_chars[i]);
+                        printlim(opts, &limit, &limits_tbl[i]);
+                }
+                return EXIT_SUCCESS;
+        }
 
-                if (opt_char == 1)
+        /* Second pass: set or print limits, in order */
+        GETOPT_RESET();
+        while (1) {
+                char *val_str;
+                int opt_char = getopt(argc, argv, ulimit_opt_string);
+
+                if (opt_char == -1)
+                        break;
+                if (opt_char == 'H')
+                        continue;
+                if (opt_char == 'S')
+                        continue;
+                //if (opt_char == 'a') - impossible
+
+                if (opt_char == 1) /* if "ulimit NNN", -f is assumed */
                         opt_char = 'f';
-                for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
-                        if (opt_char == l->option) {
-                                char *val_str;
-
-                                getrlimit(l->cmd, &limit);
-
-                                val_str = optarg;
-                                if (!val_str && argv[optind] && argv[optind][0] != '-')
-                                        val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
-                                if (val_str) {
-                                        rlim_t val;
-
-                                        if (strcmp(val_str, "unlimited") == 0)
-                                                val = RLIM_INFINITY;
-                                        else {
-                                                if (sizeof(val) == sizeof(int))
-                                                        val = bb_strtou(val_str, NULL, 10);
-                                                else if (sizeof(val) == sizeof(long))
-                                                        val = bb_strtoul(val_str, NULL, 10);
-                                                else
-                                                        val = bb_strtoull(val_str, NULL, 10);
-                                                if (errno) {
-                                                        bb_error_msg("invalid number '%s'", val_str);
-                                                        return EXIT_FAILURE;
-                                                }
-                                                val <<= l->factor_shift;
-                                        }
-//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
-                                        /* from man bash: "If neither -H nor -S
-                                         * is specified, both the soft and hard
-                                         * limits are set. */
-                                        if (!opts)
-                                                opts = OPT_hard + OPT_soft;
-                                        if (opts & OPT_hard)
-                                                limit.rlim_max = val;
-                                        if (opts & OPT_soft)
-                                                limit.rlim_cur = val;
-//bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
-                                        if (setrlimit(l->cmd, &limit) < 0) {
-                                                bb_perror_msg("error setting limit");
-                                                return EXIT_FAILURE;
-                                        }
-                                } else {
-                                        printlim(opts, &limit, l);
+                i = strchrnul(limit_chars, opt_char) - limit_chars;
+                //if (i >= ARRAY_SIZE(limits_tbl)) - bad option, impossible
+
+                val_str = optarg;
+                if (!val_str && argv[optind] && argv[optind][0] != '-')
+                        val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
+
+                getrlimit(limits_tbl[i].cmd, &limit);
+                if (!val_str) {
+                        if (opt_cnt > 1)
+                                printf("%-32s(-%c) ", limits_tbl[i].name, limit_chars[i]);
+                        printlim(opts, &limit, &limits_tbl[i]);
+                } else {
+                        rlim_t val = RLIM_INFINITY;
+                        if (strcmp(val_str, "unlimited") != 0) {
+                                if (sizeof(val) == sizeof(int))
+                                        val = bb_strtou(val_str, NULL, 10);
+                                else if (sizeof(val) == sizeof(long))
+                                        val = bb_strtoul(val_str, NULL, 10);
+                                else
+                                        val = bb_strtoull(val_str, NULL, 10);
+                                if (errno) {
+                                        bb_error_msg("invalid number '%s'", val_str);
+                                        return EXIT_FAILURE;
                                 }
-                                break;
+                                val <<= limits_tbl[i].factor_shift;
+                        }
+//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
+                        /* from man bash: "If neither -H nor -S
+                         * is specified, both the soft and hard
+                         * limits are set. */
+                        if (opts & OPT_hard)
+                                limit.rlim_max = val;
+                        if (opts & OPT_soft)
+                                limit.rlim_cur = val;
+//bb_error_msg("setrlimit(%d, %lld, %lld)", limits_tbl[i].cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
+                        if (setrlimit(limits_tbl[i].cmd, &limit) < 0) {
+                                bb_perror_msg("error setting limit");
+                                return EXIT_FAILURE;
                         }
-                } /* for (every possible opt) */
-
-                if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) {
-                        /* bad option. getopt already complained. */
-                        break;
                 }
         } /* while (there are options) */
 
-        return 0;
+        if (opt_cnt == 0) {
+                /* "bare ulimit": treat it as if it was -f */
+                getrlimit(limits_tbl[LIMIT_F_IDX].cmd, &limit);
+                printlim(opts, &limit, &limits_tbl[LIMIT_F_IDX]);
+        }
+
+        return EXIT_SUCCESS;
 }
 #else
 int FAST_FUNC shell_builtin_ulimit(char **argv UNUSED_PARAM)
diff --git a/shell/shell_common.h b/shell/shell_common.h
index a1323021d..7b478f1df 100644
--- a/shell/shell_common.h
+++ b/shell/shell_common.h
@@ -26,8 +26,6 @@ extern const char defifsvar[] ALIGN1; /* "IFS= \t\n" */
 
 extern const char defoptindvar[] ALIGN1; /* "OPTIND=1" */
 
-int FAST_FUNC is_well_formed_var_name(const char *s, char terminator);
-
 /* Builtins */
 
 struct builtin_read_params {