1 files changed, 103 insertions, 46 deletions

diff --git a/shell/ash.c b/shell/ash.c
index dc5561765..28b522d7c 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -31,15 +31,14 @@
  */
 
 //config:config ASH
-//config:       bool "ash"
+//config:       bool "ash (77 kb)"
 //config:       default y
 //config:       depends on !NOMMU
 //config:       help
-//config:         Tha 'ash' shell adds about 60k in the default configuration and is
-//config:         the most complete and most pedantically correct shell included with
-//config:         busybox. This shell is actually a derivative of the Debian 'dash'
-//config:         shell (by Herbert Xu), which was created by porting the 'ash' shell
-//config:         (written by Kenneth Almquist) from NetBSD.
+//config:       The most complete and most pedantically correct shell included with
+//config:       busybox. This shell is actually a derivative of the Debian 'dash'
+//config:       shell (by Herbert Xu), which was created by porting the 'ash' shell
+//config:       (written by Kenneth Almquist) from NetBSD.
 //config:
 //config:# ash options
 //config:# note: Don't remove !NOMMU part in the next line; it would break
@@ -56,11 +55,11 @@
 //config:       default y       # Y is bigger, but because of uclibc glob() bug, let Y be default for now
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         Do not use glob() function from libc, use internal implementation.
-//config:         Use this if you are getting "glob.h: No such file or directory"
-//config:         or similar build errors.
-//config:         Note that as of now (2017-01), uclibc and musl glob() both have bugs
-//config:         which would break ash if you select N here.
+//config:       Do not use glob() function from libc, use internal implementation.
+//config:       Use this if you are getting "glob.h: No such file or directory"
+//config:       or similar build errors.
+//config:       Note that as of now (2017-01), uclibc and musl glob() both have bugs
+//config:       which would break ash if you select N here.
 //config:
 //config:config ASH_BASH_COMPAT
 //config:       bool "bash-compatible extensions"
@@ -82,37 +81,37 @@
 //config:       default y
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         Enable pseudorandom generator and dynamic variable "$RANDOM".
-//config:         Each read of "$RANDOM" will generate a new pseudorandom value.
-//config:         You can reset the generator by using a specified start value.
-//config:         After "unset RANDOM" the generator will switch off and this
-//config:         variable will no longer have special treatment.
+//config:       Enable pseudorandom generator and dynamic variable "$RANDOM".
+//config:       Each read of "$RANDOM" will generate a new pseudorandom value.
+//config:       You can reset the generator by using a specified start value.
+//config:       After "unset RANDOM" the generator will switch off and this
+//config:       variable will no longer have special treatment.
 //config:
 //config:config ASH_EXPAND_PRMT
 //config:       bool "Expand prompt string"
 //config:       default y
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         $PS# may contain volatile content, such as backquote commands.
-//config:         This option recreates the prompt string from the environment
-//config:         variable each time it is displayed.
+//config:       $PS# may contain volatile content, such as backquote commands.
+//config:       This option recreates the prompt string from the environment
+//config:       variable each time it is displayed.
 //config:
 //config:config ASH_IDLE_TIMEOUT
 //config:       bool "Idle timeout variable $TMOUT"
 //config:       default y
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         Enable bash-like auto-logout after $TMOUT seconds of idle time.
+//config:       Enable bash-like auto-logout after $TMOUT seconds of idle time.
 //config:
 //config:config ASH_MAIL
 //config:       bool "Check for new mail in interactive shell"
 //config:       default y
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         Enable "check for new mail" function:
-//config:         if set, $MAIL file and $MAILPATH list of files
-//config:         are checked for mtime changes, and "you have mail"
-//config:         message is printed if change is detected.
+//config:       Enable "check for new mail" function:
+//config:       if set, $MAIL file and $MAILPATH list of files
+//config:       are checked for mtime changes, and "you have mail"
+//config:       message is printed if change is detected.
 //config:
 //config:config ASH_ECHO
 //config:       bool "echo builtin"
@@ -144,9 +143,9 @@
 //config:       default y
 //config:       depends on ASH || SH_IS_ASH || BASH_IS_ASH
 //config:       help
-//config:         Enable support for the 'command' builtin, which allows
-//config:         you to run the specified command or builtin,
-//config:         even when there is a function with the same name.
+//config:       Enable support for the 'command' builtin, which allows
+//config:       you to run the specified command or builtin,
+//config:       even when there is a function with the same name.
 //config:
 //config:
 //config:config ASH_NOCONSOLE
@@ -1746,7 +1745,7 @@ static char *
 stack_nputstr(const char *s, size_t n, char *p)
 {
         p = makestrspace(n, p);
-        p = (char *)memcpy(p, s, n) + n;
+        p = (char *)mempcpy(p, s, n);
         return p;
 }
 
@@ -1830,7 +1829,7 @@ number(const char *s)
 }
 
 /*
- * Produce a possibly single quoted string suitable as input to the shell.
+ * Produce a single quoted string suitable as input to the shell.
  * The return string is allocated on the stack.
  */
 static char *
@@ -1849,7 +1848,7 @@ single_quote(const char *s)
                 q = p = makestrspace(len + 3, p);
 
                 *q++ = '\'';
-                q = (char *)memcpy(q, s, len) + len;
+                q = (char *)mempcpy(q, s, len);
                 *q++ = '\'';
                 s += len;
 
@@ -1863,7 +1862,7 @@ single_quote(const char *s)
                 q = p = makestrspace(len + 3, p);
 
                 *q++ = '"';
-                q = (char *)memcpy(q, s - len, len) + len;
+                q = (char *)mempcpy(q, s - len, len);
                 *q++ = '"';
 
                 STADJUST(q - p, p);
@@ -1874,6 +1873,47 @@ single_quote(const char *s)
         return stackblock();
 }
 
+/*
+ * 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.
+ */
+static const char *
+maybe_single_quote(const char *s)
+{
+        const char *p = s;
+
+        while (*p) {
+                /* Assuming ACSII */
+                /* quote ctrl_chars space !"#$%&'()* */
+                if (*p < '+')
+                        goto need_quoting;
+                /* quote ;<=>? */
+                if (*p >= ';' && *p <= '?')
+                        goto need_quoting;
+                /* quote `[\ */
+                if (*p == '`')
+                        goto need_quoting;
+                if (*p == '[')
+                        goto need_quoting;
+                if (*p == '\\')
+                        goto need_quoting;
+                /* quote {|}~ DEL and high bytes */
+                if (*p > 'z')
+                        goto need_quoting;
+                /* Not quoting these: +,-./ 0-9 :@ A-Z ]^_ a-z */
+                /* TODO: maybe avoid quoting % */
+                p++;
+        }
+        return s;
+
+ need_quoting:
+        return single_quote(s);
+}
+
 
 /* ============ nextopt */
 
@@ -2362,10 +2402,10 @@ setvar(const char *name, const char *val, int flags)
 
         INT_OFF;
         nameeq = ckmalloc(namelen + vallen + 2);
-        p = memcpy(nameeq, name, namelen) + namelen;
+        p = mempcpy(nameeq, name, namelen);
         if (val) {
                 *p++ = '=';
-                p = memcpy(p, val, vallen) + vallen;
+                p = mempcpy(p, val, vallen);
         }
         *p = '\0';
         setvareq(nameeq, flags | VNOSAVE);
@@ -2512,8 +2552,7 @@ path_advance(const char **path, const char *name)
                 growstackblock();
         q = stackblock();
         if (p != start) {
-                memcpy(q, start, p - start);
-                q += p - start;
+                q = mempcpy(q, start, p - start);
                 *q++ = '/';
         }
         strcpy(q, name);
@@ -6277,7 +6316,7 @@ rmescapes(char *str, int flag)
                 }
                 q = r;
                 if (len > 0) {
-                        q = (char *)memcpy(q, str, len) + len;
+                        q = (char *)mempcpy(q, str, len);
                 }
         }
 
@@ -10161,18 +10200,36 @@ evalcommand(union node *cmd, int flags)
 
         /* Print the command if xflag is set. */
         if (xflag) {
-                int n;
-                const char *p = " %s" + 1;
+                const char *pfx = "";
+
+                fdprintf(preverrout_fd, "%s", expandstr(ps4val()));
 
-                fdprintf(preverrout_fd, p, expandstr(ps4val()));
                 sp = varlist.list;
-                for (n = 0; n < 2; n++) {
-                        while (sp) {
-                                fdprintf(preverrout_fd, p, sp->text);
-                                sp = sp->next;
-                                p = " %s";
-                        }
-                        sp = arglist.list;
+                while (sp) {
+                        char *varval = sp->text;
+                        char *eq = strchrnul(varval, '=');
+                        if (*eq)
+                                eq++;
+                        fdprintf(preverrout_fd, "%s%.*s%s",
+                                pfx,
+                                (int)(eq - varval), varval,
+                                maybe_single_quote(eq)
+                        );
+                        sp = sp->next;
+                        pfx = " ";
+                }
+
+                sp = arglist.list;
+                while (sp) {
+                        fdprintf(preverrout_fd, "%s%s",
+                                pfx,
+                                /* always quote if matches reserved word: */
+                                findkwd(sp->text)
+                                ? single_quote(sp->text)
+                                : maybe_single_quote(sp->text)
+                        );
+                        sp = sp->next;
+                        pfx = " ";
                 }
                 safe_write(preverrout_fd, "\n", 1);
         }