1 files changed, 219 insertions, 240 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 28b522d7c..6aaeecfac 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -241,6 +241,9 @@
 #include "shell_common.h"
 #if ENABLE_FEATURE_SH_MATH
 # include "math.h"
+#else
+typedef long arith_t;
+# define ARITH_FMT "%ld"
 #endif
 #if ENABLE_ASH_RANDOM_SUPPORT
 # include "random.h"
@@ -708,8 +711,8 @@ fmtstr(char *outbuf, size_t length, const char *fmt, ...)
         va_list ap;
         int ret;
 
-        va_start(ap, fmt);
         INT_OFF;
+        va_start(ap, fmt);
         ret = vsnprintf(outbuf, length, fmt, ap);
         va_end(ap);
         INT_ON;
@@ -1334,7 +1337,6 @@ static struct parsefile basepf;        /* top level input file */
 static struct parsefile *g_parsefile = &basepf;  /* current input file */
 static int startlinno;                 /* line # where last token started */
 static char *commandname;              /* currently executing command */
-static struct strlist *cmdenviron;     /* environment for builtin command */
 
 
 /* ============ Message printing */
@@ -1391,6 +1393,18 @@ ash_msg_and_raise_error(const char *msg, ...)
         va_end(ap);
 }
 
+/*
+ * Use '%m' to append error string on platforms that support it, '%s' and
+ * strerror() on those that don't.
+ *
+ * 'fmt' must be a string literal.
+ */
+#ifdef HAVE_PRINTF_PERCENTM
+#define ash_msg_and_raise_perror(fmt, ...) ash_msg_and_raise_error(fmt ": %m", ##__VA_ARGS__)
+#else
+#define ash_msg_and_raise_perror(fmt, ...) ash_msg_and_raise_error(fmt ": %s", ##__VA_ARGS__, strerror(errno))
+#endif
+
 static void raise_error_syntax(const char *) NORETURN;
 static void
 raise_error_syntax(const char *msg)
@@ -1875,9 +1889,6 @@ single_quote(const char *s)
 
 /*
  * Produce a possibly single quoted string suitable as input to the shell.
- * If 'conditional' is nonzero, quoting is only done if the string contains
- * non-shellsafe characters, or is identical to a shell keyword (reserved
- * word); if it is zero, quoting is always done.
  * If quoting was done, the return string is allocated on the stack,
  * otherwise a pointer to the original string is returned.
  */
@@ -2312,15 +2323,9 @@ reinit_unicode_for_ash(void)
 /*
  * Search the environment of a builtin command.
  */
-static const char *
+static ALWAYS_INLINE const char *
 bltinlookup(const char *name)
 {
-        struct strlist *sp;
-
-        for (sp = cmdenviron; sp; sp = sp->next) {
-                if (varcmp(sp->text, name) == 0)
-                        return var_end(sp->text);
-        }
         return lookupvar(name);
 }
 
@@ -2331,14 +2336,15 @@ bltinlookup(const char *name)
  * will go away.
  * Called with interrupts off.
  */
-static void
+static struct var *
 setvareq(char *s, int flags)
 {
         struct var *vp, **vpp;
 
         vpp = hashvar(s);
         flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
-        vp = *findvar(vpp, s);
+        vpp = findvar(vpp, s);
+        vp = *vpp;
         if (vp) {
                 if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) {
                         const char *n;
@@ -2351,7 +2357,7 @@ setvareq(char *s, int flags)
                 }
 
                 if (flags & VNOSET)
-                        return;
+                        goto out;
 
                 if (vp->var_func && !(flags & VNOFUNC))
                         vp->var_func(var_end(s));
@@ -2359,11 +2365,22 @@ setvareq(char *s, int flags)
                 if (!(vp->flags & (VTEXTFIXED|VSTACK)))
                         free((char*)vp->var_text);
 
+                if (((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) | (vp->flags & VSTRFIXED)) == VUNSET) {
+                        *vpp = vp->next;
+                        free(vp);
+ out_free:
+                        if ((flags & (VTEXTFIXED|VSTACK|VNOSAVE)) == VNOSAVE)
+                                free(s);
+                        goto out;
+                }
+
                 flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
         } else {
                 /* variable s is not found */
                 if (flags & VNOSET)
-                        return;
+                        goto out;
+                if ((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) == VUNSET)
+                        goto out_free;
                 vp = ckzalloc(sizeof(*vp));
                 vp->next = *vpp;
                 /*vp->func = NULL; - ckzalloc did it */
@@ -2373,13 +2390,16 @@ setvareq(char *s, int flags)
                 s = ckstrdup(s);
         vp->var_text = s;
         vp->flags = flags;
+
+ out:
+        return vp;
 }
 
 /*
  * Set the value of a variable.  The flags argument is ored with the
  * flags of the variable.  If val is NULL, the variable is unset.
  */
-static void
+static struct var *
 setvar(const char *name, const char *val, int flags)
 {
         const char *q;
@@ -2387,6 +2407,7 @@ setvar(const char *name, const char *val, int flags)
         char *nameeq;
         size_t namelen;
         size_t vallen;
+        struct var *vp;
 
         q = endofname(name);
         p = strchrnul(q, '=');
@@ -2408,8 +2429,10 @@ setvar(const char *name, const char *val, int flags)
                 p = mempcpy(p, val, vallen);
         }
         *p = '\0';
-        setvareq(nameeq, flags | VNOSAVE);
+        vp = setvareq(nameeq, flags | VNOSAVE);
         INT_ON;
+
+        return vp;
 }
 
 static void FAST_FUNC
@@ -2421,43 +2444,10 @@ setvar0(const char *name, const char *val)
 /*
  * Unset the specified variable.
  */
-static int
+static void
 unsetvar(const char *s)
 {
-        struct var **vpp;
-        struct var *vp;
-        int retval;
-
-        vpp = findvar(hashvar(s), s);
-        vp = *vpp;
-        retval = 2;
-        if (vp) {
-                int flags = vp->flags;
-
-                retval = 1;
-                if (flags & VREADONLY)
-                        goto out;
-#if ENABLE_ASH_RANDOM_SUPPORT
-                vp->flags &= ~VDYNAMIC;
-#endif
-                if (flags & VUNSET)
-                        goto ok;
-                if ((flags & VSTRFIXED) == 0) {
-                        INT_OFF;
-                        if ((flags & (VTEXTFIXED|VSTACK)) == 0)
-                                free((char*)vp->var_text);
-                        *vpp = vp->next;
-                        free(vp);
-                        INT_ON;
-                } else {
-                        setvar0(s, NULL);
-                        vp->flags &= ~VEXPORT;
-                }
- ok:
-                retval = 0;
-        }
- out:
-        return retval;
+        setvar(s, NULL, 0);
 }
 
 /*
@@ -4067,7 +4057,7 @@ static void
 xtcsetpgrp(int fd, pid_t pgrp)
 {
         if (tcsetpgrp(fd, pgrp))
-                ash_msg_and_raise_error("can't set tty process group (%m)");
+                ash_msg_and_raise_perror("can't set tty process group");
 }
 
 /*
@@ -5529,68 +5519,6 @@ stoppedjobs(void)
 #define CLOSED -3               /* marks a slot of previously-closed fd */
 
 /*
- * Open a file in noclobber mode.
- * The code was copied from bash.
- */
-static int
-noclobberopen(const char *fname)
-{
-        int r, fd;
-        struct stat finfo, finfo2;
-
-        /*
-         * If the file exists and is a regular file, return an error
-         * immediately.
-         */
-        r = stat(fname, &finfo);
-        if (r == 0 && S_ISREG(finfo.st_mode)) {
-                errno = EEXIST;
-                return -1;
-        }
-
-        /*
-         * If the file was not present (r != 0), make sure we open it
-         * exclusively so that if it is created before we open it, our open
-         * will fail.  Make sure that we do not truncate an existing file.
-         * Note that we don't turn on O_EXCL unless the stat failed -- if the
-         * file was not a regular file, we leave O_EXCL off.
-         */
-        if (r != 0)
-                return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
-        fd = open(fname, O_WRONLY|O_CREAT, 0666);
-
-        /* If the open failed, return the file descriptor right away. */
-        if (fd < 0)
-                return fd;
-
-        /*
-         * OK, the open succeeded, but the file may have been changed from a
-         * non-regular file to a regular file between the stat and the open.
-         * We are assuming that the O_EXCL open handles the case where FILENAME
-         * did not exist and is symlinked to an existing file between the stat
-         * and open.
-         */
-
-        /*
-         * If we can open it and fstat the file descriptor, and neither check
-         * revealed that it was a regular file, and the file has not been
-         * replaced, return the file descriptor.
-         */
-        if (fstat(fd, &finfo2) == 0
-         && !S_ISREG(finfo2.st_mode)
-         && finfo.st_dev == finfo2.st_dev
-         && finfo.st_ino == finfo2.st_ino
-        ) {
-                return fd;
-        }
-
-        /* The file has been replaced.  badness. */
-        close(fd);
-        errno = EEXIST;
-        return -1;
-}
-
-/*
  * Handle here documents.  Normally we fork off a process to write the
  * data to a pipe.  If the document is short, we can stuff the data in
  * the pipe without forking.
@@ -5645,6 +5573,7 @@ openhere(union node *redir)
 static int
 openredirect(union node *redir)
 {
+        struct stat sb;
         char *fname;
         int f;
 
@@ -5709,9 +5638,23 @@ openredirect(union node *redir)
 #endif
                 /* Take care of noclobber mode. */
                 if (Cflag) {
-                        f = noclobberopen(fname);
-                        if (f < 0)
+                        if (stat(fname, &sb) < 0) {
+                                f = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
+                                if (f < 0)
+                                        goto ecreate;
+                        } else if (!S_ISREG(sb.st_mode)) {
+                                f = open(fname, O_WRONLY, 0666);
+                                if (f < 0)
+                                        goto ecreate;
+                                if (fstat(f, &sb) < 0 && S_ISREG(sb.st_mode)) {
+                                        close(f);
+                                        errno = EEXIST;
+                                        goto ecreate;
+                                }
+                        } else {
+                                errno = EEXIST;
                                 goto ecreate;
+                        }
                         break;
                 }
                 /* FALLTHROUGH */
@@ -5750,7 +5693,7 @@ savefd(int from)
         err = newfd < 0 ? errno : 0;
         if (err != EBADF) {
                 if (err)
-                        ash_msg_and_raise_error("%d: %m", from);
+                        ash_msg_and_raise_perror("%d", from);
                 close(from);
                 fcntl(newfd, F_SETFD, FD_CLOEXEC);
         }
@@ -5765,7 +5708,7 @@ dup2_or_raise(int from, int to)
         newfd = (from != to) ? dup2(from, to) : to;
         if (newfd < 0) {
                 /* Happens when source fd is not open: try "echo >&99" */
-                ash_msg_and_raise_error("%d: %m", from);
+                ash_msg_and_raise_perror("%d", from);
         }
         return newfd;
 }
@@ -5896,7 +5839,7 @@ redirect(union node *redir, int flags)
                         /* "echo >&10" and 10 is a fd opened to a sh script? */
                         if (is_hidden_fd(sv, right_fd)) {
                                 errno = EBADF; /* as if it is closed */
-                                ash_msg_and_raise_error("%d: %m", right_fd);
+                                ash_msg_and_raise_perror("%d", right_fd);
                         }
                         newfd = -1;
                 } else {
@@ -5930,7 +5873,7 @@ redirect(union node *redir, int flags)
                                         if (newfd >= 0)
                                                 close(newfd);
                                         errno = i;
-                                        ash_msg_and_raise_error("%d: %m", fd);
+                                        ash_msg_and_raise_perror("%d", fd);
                                         /* NOTREACHED */
                                 }
                                 /* EBADF: it is not open - good, remember to close it */
@@ -6104,7 +6047,7 @@ ash_arith(const char *s)
 #define RMESCAPE_SLASH  0x20    /* Stop globbing after slash */
 
 /* Add CTLESC when necessary. */
-#define QUOTES_ESC     (EXP_FULL | EXP_CASE | EXP_QPAT | EXP_REDIR)
+#define QUOTES_ESC     (EXP_FULL | EXP_CASE | EXP_QPAT)
 /* Do not skip NUL characters. */
 #define QUOTES_KEEPNUL EXP_TILDE
 
@@ -6137,19 +6080,20 @@ static struct arglist exparg;
 
 /*
  * Our own itoa().
+ * cvtnum() is used even if math support is off (to prepare $? values and such).
  */
-#if !ENABLE_FEATURE_SH_MATH
-/* cvtnum() is used even if math support is off (to prepare $? values and such) */
-typedef long arith_t;
-# define ARITH_FMT "%ld"
-#endif
 static int
 cvtnum(arith_t num)
 {
         int len;
 
-        expdest = makestrspace(sizeof(arith_t)*3 + 2, expdest);
-        len = fmtstr(expdest, sizeof(arith_t)*3 + 2, ARITH_FMT, num);
+        /* 32-bit and wider ints require buffer size of bytes*3 (or less) */
+        len = sizeof(arith_t) * 3;
+        /* If narrower: worst case, 1-byte ints: need 5 bytes: "-127<NUL>" */
+        if (sizeof(arith_t) < 4) len += 2;
+
+        expdest = makestrspace(len, expdest);
+        len = fmtstr(expdest, len, ARITH_FMT, num);
         STADJUST(len, expdest);
         return len;
 }
@@ -6569,9 +6513,24 @@ struct backcmd {                /* result of evalbackcmd */
 };
 
 /* These forward decls are needed to use "eval" code for backticks handling: */
-#define EV_EXIT 01              /* exit after evaluating tree */
+/* flags in argument to evaltree */
+#define EV_EXIT    01           /* exit after evaluating tree */
+#define EV_TESTED  02           /* exit status is checked; ignore -e flag */
 static int evaltree(union node *, int);
 
+/* An evaltree() which is known to never return.
+ * Used to use an alias:
+ * static int evaltreenr(union node *, int) __attribute__((alias("evaltree"),__noreturn__));
+ * but clang was reported to "transfer" noreturn-ness to evaltree() as well.
+ */
+static ALWAYS_INLINE NORETURN void
+evaltreenr(union node *n, int flags)
+{
+        evaltree(n, flags);
+        bb_unreachable(abort());
+        /* NOTREACHED */
+}
+
 static void FAST_FUNC
 evalbackcmd(union node *n, struct backcmd *result)
 {
@@ -6617,7 +6576,7 @@ evalbackcmd(union node *n, struct backcmd *result)
  */
                 eflag = 0;
                 ifsfree();
-                evaltree(n, EV_EXIT); /* actually evaltreenr... */
+                evaltreenr(n, EV_EXIT);
                 /* NOTREACHED */
         }
 #endif
@@ -6750,19 +6709,15 @@ expari(int flag)
 #endif
 
 /* argstr needs it */
-static char *evalvar(char *p, int flags, struct strlist *var_str_list);
+static char *evalvar(char *p, int flags);
 
 /*
  * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
  * characters to allow for further processing.  Otherwise treat
  * $@ like $* since no splitting will be performed.
- *
- * var_str_list (can be NULL) is a list of "VAR=val" strings which take precedence
- * over shell variables. Needed for "A=a B=$A; echo $B" case - we use it
- * for correct expansion of "B=$A" word.
  */
 static void
-argstr(char *p, int flags, struct strlist *var_str_list)
+argstr(char *p, int flags)
 {
         static const char spclchars[] ALIGN1 = {
                 '=',
@@ -6855,7 +6810,7 @@ argstr(char *p, int flags, struct strlist *var_str_list)
                         inquotes ^= EXP_QUOTED;
                         /* "$@" syntax adherence hack */
                         if (inquotes && !memcmp(p, dolatstr + 1, DOLATSTRLEN - 1)) {
-                                p = evalvar(p + 1, flags | inquotes, /* var_str_list: */ NULL) + 1;
+                                p = evalvar(p + 1, flags | inquotes) + 1;
                                 goto start;
                         }
  addquote:
@@ -6881,7 +6836,7 @@ argstr(char *p, int flags, struct strlist *var_str_list)
                         goto addquote;
                 case CTLVAR:
                         TRACE(("argstr: evalvar('%s')\n", p));
-                        p = evalvar(p, flags | inquotes, var_str_list);
+                        p = evalvar(p, flags | inquotes);
                         TRACE(("argstr: evalvar:'%s'\n", (char *)stackblock()));
                         goto start;
                 case CTLBACKQ:
@@ -7023,7 +6978,7 @@ varunset(const char *end, const char *var, const char *umsg, int varflags)
 
 static const char *
 subevalvar(char *p, char *varname, int strloc, int subtype,
-                int startloc, int varflags, int flag, struct strlist *var_str_list)
+                int startloc, int varflags, int flag)
 {
         struct nodelist *saveargbackq = argbackq;
         int quotes = flag & QUOTES_ESC;
@@ -7041,8 +6996,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
         //              p, varname, strloc, subtype, startloc, varflags, quotes);
 
         argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
-                        (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0),
-                        var_str_list);
+                        (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0)
+        );
         STPUTC('\0', expdest);
         argbackq = saveargbackq;
         startp = (char *)stackblock() + startloc;
@@ -7319,7 +7274,7 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
  * ash -c 'echo ${#1#}'  name:'1=#'
  */
 static NOINLINE ssize_t
-varvalue(char *name, int varflags, int flags, struct strlist *var_str_list, int *quotedp)
+varvalue(char *name, int varflags, int flags, int *quotedp)
 {
         const char *p;
         int num;
@@ -7411,31 +7366,6 @@ varvalue(char *name, int varflags, int flags, struct strlist *var_str_list, int
                 goto value;
         default:
                 /* NB: name has form "VAR=..." */
-
-                /* "A=a B=$A" case: var_str_list is a list of "A=a" strings
-                 * which should be considered before we check variables. */
-                if (var_str_list) {
-                        unsigned name_len = (strchrnul(name, '=') - name) + 1;
-                        p = NULL;
-                        do {
-                                char *str, *eq;
-                                str = var_str_list->text;
-                                eq = strchr(str, '=');
-                                if (!eq) /* stop at first non-assignment */
-                                        break;
-                                eq++;
-                                if (name_len == (unsigned)(eq - str)
-                                 && strncmp(str, name, name_len) == 0
-                                ) {
-                                        p = eq;
-                                        /* goto value; - WRONG! */
-                                        /* think "A=1 A=2 B=$A" */
-                                }
-                                var_str_list = var_str_list->next;
-                        } while (var_str_list);
-                        if (p)
-                                goto value;
-                }
                 p = lookupvar(name);
  value:
                 if (!p)
@@ -7465,7 +7395,7 @@ varvalue(char *name, int varflags, int flags, struct strlist *var_str_list, int
  * input string.
  */
 static char *
-evalvar(char *p, int flag, struct strlist *var_str_list)
+evalvar(char *p, int flag)
 {
         char varflags;
         char subtype;
@@ -7489,7 +7419,7 @@ evalvar(char *p, int flag, struct strlist *var_str_list)
         p = strchr(p, '=') + 1; //TODO: use var_end(p)?
 
  again:
-        varlen = varvalue(var, varflags, flag, var_str_list, &quoted);
+        varlen = varvalue(var, varflags, flag, &quoted);
         if (varflags & VSNUL)
                 varlen--;
 
@@ -7503,8 +7433,7 @@ evalvar(char *p, int flag, struct strlist *var_str_list)
                 if (varlen < 0) {
                         argstr(
                                 p,
-                                flag | EXP_TILDE | EXP_WORD,
-                                var_str_list
+                                flag | EXP_TILDE | EXP_WORD
                         );
                         goto end;
                 }
@@ -7516,7 +7445,7 @@ evalvar(char *p, int flag, struct strlist *var_str_list)
                         goto record;
 
                 subevalvar(p, var, 0, subtype, startloc, varflags,
-                           flag & ~QUOTES_ESC, var_str_list);
+                           flag & ~QUOTES_ESC);
                 varflags &= ~VSNUL;
                 /*
                  * Remove any recorded regions beyond
@@ -7569,7 +7498,7 @@ evalvar(char *p, int flag, struct strlist *var_str_list)
                 STPUTC('\0', expdest);
                 patloc = expdest - (char *)stackblock();
                 if (NULL == subevalvar(p, /* varname: */ NULL, patloc, subtype,
-                                startloc, varflags, flag, var_str_list)) {
+                                startloc, varflags, flag)) {
                         int amount = expdest - (
                                 (char *)stackblock() + patloc - 1
                         );
@@ -7993,8 +7922,7 @@ expandarg(union node *arg, struct arglist *arglist, int flag)
         argbackq = arg->narg.backquote;
         STARTSTACKSTR(expdest);
         TRACE(("expandarg: argstr('%s',flags:%x)\n", arg->narg.text, flag));
-        argstr(arg->narg.text, flag,
-                        /* var_str_list: */ arglist ? arglist->list : NULL);
+        argstr(arg->narg.text, flag);
         p = _STPUTC('\0', expdest);
         expdest = p - 1;
         if (arglist == NULL) {
@@ -8013,10 +7941,6 @@ expandarg(union node *arg, struct arglist *arglist, int flag)
                 exparg.lastp = &exparg.list;
                 expandmeta(exparg.list /*, flag*/);
         } else {
-                if (flag & EXP_REDIR) { /*XXX - for now, just remove escapes */
-                        rmescapes(p, 0);
-                        TRACE(("expandarg: rmescapes:'%s'\n", p));
-                }
                 sp = stzalloc(sizeof(*sp));
                 sp->text = p;
                 *exparg.lastp = sp;
@@ -8065,8 +7989,7 @@ casematch(union node *pattern, char *val)
         setstackmark(&smark);
         argbackq = pattern->narg.backquote;
         STARTSTACKSTR(expdest);
-        argstr(pattern->narg.text, EXP_TILDE | EXP_CASE,
-                        /* var_str_list: */ NULL);
+        argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
         STACKSTRNUL(expdest);
         ifsfree();
         result = patmatch(stackblock(), val);
@@ -8144,7 +8067,7 @@ static int builtinloc = -1;     /* index in path of %builtin, or -1 */
 
 
 static void
-tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **envp)
+tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) const char *cmd, char **argv, char **envp)
 {
 #if ENABLE_FEATURE_SH_STANDALONE
         if (applet_no >= 0) {
@@ -8152,6 +8075,7 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **
                         clearenv();
                         while (*envp)
                                 putenv(*envp++);
+                        popredir(/*drop:*/ 1, /*restore:*/ 0);
                         run_applet_no_and_exit(applet_no, cmd, argv);
                 }
                 /* re-exec ourselves with the new arguments */
@@ -8169,7 +8093,7 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **
 #else
         execve(cmd, argv, envp);
 #endif
-        if (cmd != (char*) bb_busybox_exec_path && errno == ENOEXEC) {
+        if (cmd != bb_busybox_exec_path && errno == ENOEXEC) {
                 /* Run "cmd" as a shell script:
                  * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
                  * "If the execve() function fails with ENOEXEC, the shell
@@ -8186,8 +8110,8 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **
                  * message and exit code 126. For one, this prevents attempts
                  * to interpret foreign ELF binaries as shell scripts.
                  */
-                argv[0] = cmd;
-                cmd = (char*) bb_busybox_exec_path;
+                argv[0] = (char*) cmd;
+                cmd = bb_busybox_exec_path;
                 /* NB: this is only possible because all callers of shellexec()
                  * ensure that the argv[-1] slot exists!
                  */
@@ -8810,10 +8734,6 @@ static int nodeptrsize;
 static char **nodeptr;
 #endif
 
-/* flags in argument to evaltree */
-#define EV_EXIT    01           /* exit after evaluating tree */
-#define EV_TESTED  02           /* exit status is checked; ignore -e flag */
-
 static const uint8_t nodesize[N_NUMBER] ALIGN1 = {
         [NCMD     ] = SHELL_ALIGN(sizeof(struct ncmd)),
         [NPIPE    ] = SHELL_ALIGN(sizeof(struct npipe)),
@@ -9336,11 +9256,6 @@ evaltree(union node *n, int flags)
         return exitstatus;
 }
 
-#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
-static
-#endif
-int evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__));
-
 static int
 skiploop(void)
 {
@@ -9699,27 +9614,57 @@ optschanged(void)
 #endif
 }
 
-static struct localvar *localvars;
+struct localvar_list {
+        struct localvar_list *next;
+        struct localvar *lv;
+};
+
+static struct localvar_list *localvar_stack;
 
 /*
  * Called after a function returns.
  * Interrupts must be off.
  */
 static void
-poplocalvars(void)
+poplocalvars(int keep)
 {
-        struct localvar *lvp;
+        struct localvar_list *ll;
+        struct localvar *lvp, *next;
         struct var *vp;
 
-        while ((lvp = localvars) != NULL) {
-                localvars = lvp->next;
+        INT_OFF;
+        ll = localvar_stack;
+        localvar_stack = ll->next;
+
+        next = ll->lv;
+        free(ll);
+
+        while ((lvp = next) != NULL) {
+                next = lvp->next;
                 vp = lvp->vp;
                 TRACE(("poplocalvar %s\n", vp ? vp->var_text : "-"));
-                if (vp == NULL) {       /* $- saved */
+                if (keep) {
+                        int bits = VSTRFIXED;
+
+                        if (lvp->flags != VUNSET) {
+                                if (vp->var_text == lvp->text)
+                                        bits |= VTEXTFIXED;
+                                else if (!(lvp->flags & (VTEXTFIXED|VSTACK)))
+                                        free((char*)lvp->text);
+                        }
+
+                        vp->flags &= ~bits;
+                        vp->flags |= (lvp->flags & bits);
+
+                        if ((vp->flags &
+                             (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) == VUNSET)
+                                unsetvar(vp->var_text);
+                } else if (vp == NULL) {        /* $- saved */
                         memcpy(optlist, lvp->text, sizeof(optlist));
                         free((char*)lvp->text);
                         optschanged();
-                } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
+                } else if (lvp->flags == VUNSET) {
+                        vp->flags &= ~(VSTRFIXED|VREADONLY);
                         unsetvar(vp->var_text);
                 } else {
                         if (vp->var_func)
@@ -9731,19 +9676,43 @@ poplocalvars(void)
                 }
                 free(lvp);
         }
+        INT_ON;
+}
+
+/*
+ * Create a new localvar environment.
+ */
+static struct localvar_list *
+pushlocalvars(void)
+{
+        struct localvar_list *ll;
+
+        INT_OFF;
+        ll = ckzalloc(sizeof(*ll));
+        /*ll->lv = NULL; - zalloc did it */
+        ll->next = localvar_stack;
+        localvar_stack = ll;
+        INT_ON;
+
+        return ll->next;
+}
+
+static void
+unwindlocalvars(struct localvar_list *stop)
+{
+        while (localvar_stack != stop)
+                poplocalvars(0);
 }
 
 static int
 evalfun(struct funcnode *func, int argc, char **argv, int flags)
 {
         volatile struct shparam saveparam;
-        struct localvar *volatile savelocalvars;
         struct jmploc *volatile savehandler;
         struct jmploc jmploc;
         int e;
 
         saveparam = shellparam;
-        savelocalvars = localvars;
         savehandler = exception_handler;
         e = setjmp(jmploc.loc);
         if (e) {
@@ -9751,7 +9720,6 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         }
         INT_OFF;
         exception_handler = &jmploc;
-        localvars = NULL;
         shellparam.malloced = 0;
         func->count++;
         funcnest++;
@@ -9762,13 +9730,13 @@ evalfun(struct funcnode *func, int argc, char **argv, int flags)
         shellparam.optind = 1;
         shellparam.optoff = -1;
 #endif
+        pushlocalvars();
         evaltree(func->n.narg.next, flags & EV_TESTED);
+        poplocalvars(0);
  funcdone:
         INT_OFF;
         funcnest--;
         freefunc(func);
-        poplocalvars();
-        localvars = savelocalvars;
         freeparam(&shellparam);
         shellparam = saveparam;
         exception_handler = savehandler;
@@ -9797,7 +9765,7 @@ mklocal(char *name)
          * x=0; f() { local x=1; echo $x; local x; echo $x; }; f; echo $x
          * x=0; f() { local x=1; echo $x; local x=2; echo $x; }; f; echo $x
          */
-        lvp = localvars;
+        lvp = localvar_stack->lv;
         while (lvp) {
                 if (lvp->vp && varcmp(lvp->vp->var_text, name) == 0) {
                         if (eq)
@@ -9822,10 +9790,9 @@ mklocal(char *name)
                 if (vp == NULL) {
                         /* variable did not exist yet */
                         if (eq)
-                                setvareq(name, VSTRFIXED);
+                                vp = setvareq(name, VSTRFIXED);
                         else
-                                setvar(name, NULL, VSTRFIXED);
-                        vp = *vpp;      /* the new variable */
+                                vp = setvar(name, NULL, VSTRFIXED);
                         lvp->flags = VUNSET;
                 } else {
                         lvp->text = vp->var_text;
@@ -9842,8 +9809,8 @@ mklocal(char *name)
                 }
         }
         lvp->vp = vp;
-        lvp->next = localvars;
-        localvars = lvp;
+        lvp->next = localvar_stack->lv;
+        localvar_stack->lv = lvp;
  ret:
         INT_ON;
 }
@@ -9856,7 +9823,7 @@ localcmd(int argc UNUSED_PARAM, char **argv)
 {
         char *name;
 
-        if (!funcnest)
+        if (!localvar_stack)
                 ash_msg_and_raise_error("not in a function");
 
         argv = argptr;
@@ -10025,7 +9992,7 @@ static const struct builtincmd builtintab[] = {
 #if ENABLE_FEATURE_SH_MATH
         { BUILTIN_NOSPEC        "let"     , letcmd     },
 #endif
-        { BUILTIN_ASSIGN        "local"   , localcmd   },
+        { BUILTIN_SPEC_REG_ASSG "local"   , localcmd   },
 #if ENABLE_ASH_PRINTF
         { BUILTIN_REGULAR       "printf"  , printfcmd  },
 #endif
@@ -10115,6 +10082,7 @@ evalcommand(union node *cmd, int flags)
         static const struct builtincmd null_bltin = {
                 "\0\0", bltincmd /* why three NULs? */
         };
+        struct localvar_list *localvar_stop;
         struct stackmark smark;
         union node *argp;
         struct arglist arglist;
@@ -10136,6 +10104,7 @@ evalcommand(union node *cmd, int flags)
         /* First expand the arguments. */
         TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
         setstackmark(&smark);
+        localvar_stop = pushlocalvars();
         back_exitstatus = 0;
 
         cmdentry.cmdtype = CMDBUILTIN;
@@ -10189,6 +10158,8 @@ evalcommand(union node *cmd, int flags)
                 spp = varlist.lastp;
                 expandarg(argp, &varlist, EXP_VARTILDE);
 
+                mklocal((*spp)->text);
+
                 /*
                  * Modify the command lookup path, if a PATH= assignment
                  * is present
@@ -10354,17 +10325,12 @@ evalcommand(union node *cmd, int flags)
                 /* NOTREACHED */
         } /* default */
         case CMDBUILTIN:
-                cmdenviron = varlist.list;
-                if (cmdenviron) {
-                        struct strlist *list = cmdenviron;
-                        int i = VNOSET;
-                        if (spclbltin > 0 || argc == 0) {
-                                i = 0;
-                                if (cmd_is_exec && argc > 1)
-                                        i = VEXPORT;
-                        }
-                        listsetvar(list, i);
+                if (spclbltin > 0 || argc == 0) {
+                        poplocalvars(1);
+                        if (cmd_is_exec && argc > 1)
+                                listsetvar(varlist.list, VEXPORT);
                 }
+
                 /* Tight loop with builtins only:
                  * "while kill -0 $child; do true; done"
                  * will never exit even if $child died, unless we do this
@@ -10382,7 +10348,7 @@ evalcommand(union node *cmd, int flags)
                 goto readstatus;
 
         case CMDFUNCTION:
-                listsetvar(varlist.list, 0);
+                poplocalvars(1);
                 /* See above for the rationale */
                 dowait(DOWAIT_NONBLOCK, NULL);
                 if (evalfun(cmdentry.u.func, argc, argv, flags))
@@ -10395,6 +10361,7 @@ evalcommand(union node *cmd, int flags)
  out:
         if (cmd->ncmd.redirect)
                 popredir(/*drop:*/ cmd_is_exec, /*restore:*/ cmd_is_exec);
+        unwindlocalvars(localvar_stop);
         if (lastarg) {
                 /* dsl: I think this is intended to be used to support
                  * '_' in 'vi' command mode during line editing...
@@ -13051,6 +13018,12 @@ expandstr(const char *ps)
         return stackblock();
 }
 
+static inline int
+parser_eof(void)
+{
+        return tokpushback && lasttoken == TEOF;
+}
+
 /*
  * Execute a command or commands contained in a string.
  */
@@ -13086,7 +13059,7 @@ evalstring(char *s, int flags)
         while ((n = parsecmd(0)) != NODE_EOF) {
                 int i;
 
-                i = evaltree(n, flags);
+                i = evaltree(n, flags & ~(parser_eof() ? 0 : EV_EXIT));
                 if (n)
                         status = i;
                 popstackmark(&smark);
@@ -13237,11 +13210,12 @@ dotcmd(int argc_ UNUSED_PARAM, char **argv_ UNUSED_PARAM)
         char *fullname;
         char **argv;
         char *args_need_save;
-        struct strlist *sp;
         volatile struct shparam saveparam;
 
-        for (sp = cmdenviron; sp; sp = sp->next)
-                setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED);
+//???
+//      struct strlist *sp;
+//      for (sp = cmdenviron; sp; sp = sp->next)
+//              setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED);
 
         nextopt(nullstr); /* handle possible "--" */
         argv = argptr;
@@ -13588,13 +13562,18 @@ trapcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                 return 0;
         }
 
+        /* Why the second check?
+         * "trap NUM [sig2]..." is the same as "trap - NUM [sig2]..."
+         * In this case, NUM is signal no, not an action.
+         */
         action = NULL;
-        if (ap[1])
+        if (ap[1] && !is_number(ap[0]))
                 action = *ap++;
+
         exitcode = 0;
         while (*ap) {
                 signo = get_signum(*ap);
-                if (signo < 0 || signo >= NSIG) {
+                if (signo < 0) {
                         /* Mimic bash message exactly */
                         ash_msg("%s: invalid signal specification", *ap);
                         exitcode = 1;
@@ -13752,7 +13731,6 @@ unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
         char **ap;
         int i;
         int flag = 0;
-        int ret = 0;
 
         while ((i = nextopt("vf")) != 0) {
                 flag = i;
@@ -13760,15 +13738,13 @@ unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 
         for (ap = argptr; *ap; ap++) {
                 if (flag != 'f') {
-                        i = unsetvar(*ap);
-                        ret |= i;
-                        if (!(i & 2))
-                                continue;
+                        unsetvar(*ap);
+                        continue;
                 }
                 if (flag != 'v')
                         unsetfunc(*ap);
         }
-        return ret & 1;
+        return 0;
 }
 
 static const unsigned char timescmd_str[] ALIGN1 = {
@@ -14250,6 +14226,9 @@ reset(void)
         /* from redir.c: */
         while (redirlist)
                 popredir(/*drop:*/ 0, /*restore:*/ 0);
+
+        /* from var.c: */
+        unwindlocalvars(NULL);
 }
 
 #if PROFILE
@@ -14386,7 +14365,7 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
                 // if (!sflag) g_parsefile->pf_fd = -1;
                 // ^^ not necessary since now we special-case fd 0
                 // in is_hidden_fd() to not be considered "hidden fd"
-                evalstring(minusc, 0);
+                evalstring(minusc, sflag ? 0 : EV_EXIT);
         }
 
         if (sflag || minusc == NULL) {