ash: better fix for ash -c 'echo 5&' and ash -c 'sleep 5&'

 with testcase

diff --git a/shell/ash.c b/shell/ash.c
index 66bfa67ba305283aa4fcf344497d79f529240e65..e1df89418872efdaab4cb2c5916c0b5cc754fb1e 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -9079,8 +9079,6 @@ breakcmd(int argc UNUSED_PARAM, char **argv)
  * This implements the input routines used by the parser.
  */
 
-#define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
-
 enum {
        INPUT_PUSH_FILE = 1,
        INPUT_NOFILE_OK = 2,
@@ -9121,7 +9119,6 @@ popstring(void)
 #endif
        parsenextc = sp->prevstring;
        parsenleft = sp->prevnleft;
-/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
        g_parsefile->strpush = sp->prev;
        if (sp != &(g_parsefile->basestrpush))
                free(sp);
@@ -9137,7 +9134,7 @@ preadfd(void)
 
 #if ENABLE_FEATURE_EDITING
  retry:
-       if (!iflag || g_parsefile->fd)
+       if (!iflag || g_parsefile->fd != STDIN_FILENO)
                nr = nonblock_safe_read(g_parsefile->fd, buf, BUFSIZ - 1);
        else {
 #if ENABLE_FEATURE_TAB_COMPLETION
@@ -9185,56 +9182,76 @@ preadfd(void)
  * Refill the input buffer and return the next input character:
  *
  * 1) If a string was pushed back on the input, pop it;
- * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
+ * 2) If an EOF was pushed back (parsenleft < -BIGNUM) or we are reading
  *    from a string so we can't refill the buffer, return EOF.
  * 3) If the is more stuff in this buffer, use it else call read to fill it.
  * 4) Process input up to the next newline, deleting nul characters.
  */
+//#define pgetc_debug(...) bb_error_msg(__VA_ARGS__)
+#define pgetc_debug(...) ((void)0)
 static int
 preadbuffer(void)
 {
        char *q;
        int more;
-       char savec;
 
        while (g_parsefile->strpush) {
 #if ENABLE_ASH_ALIAS
                if (parsenleft == -1 && g_parsefile->strpush->ap
                 && parsenextc[-1] != ' ' && parsenextc[-1] != '\t'
                ) {
+                       pgetc_debug("preadbuffer PEOA");
                        return PEOA;
                }
 #endif
                popstring();
+               /* try "pgetc" now: */
+               pgetc_debug("internal pgetc at %d:%p'%s'", parsenleft, parsenextc, parsenextc);
                if (--parsenleft >= 0)
                        return signed_char2int(*parsenextc++);
        }
-       if (parsenleft == EOF_NLEFT || g_parsefile->buf == NULL)
+       /* on both branches above parsenleft < 0.
+        * "pgetc" needs refilling.
+        */
+
+       /* -90 is -BIGNUM. Below we use -99 to mark "EOF on read",
+        * pungetc() may decrement it a few times. -90 is enough.
+        */
+       if (parsenleft < -90 || g_parsefile->buf == NULL) {
+               pgetc_debug("preadbuffer PEOF1");
+               /* even in failure keep them in lock step,
+                * for correct pungetc. */
+               parsenextc++;
                return PEOF;
-       flush_stdout_stderr();
+       }
 
        more = parselleft;
        if (more <= 0) {
+               flush_stdout_stderr();
  again:
                more = preadfd();
                if (more <= 0) {
-                       parselleft = parsenleft = EOF_NLEFT;
+                       parselleft = parsenleft = -99;
+                       pgetc_debug("preadbuffer PEOF2");
+                       parsenextc++;
                        return PEOF;
                }
        }
 
+       /* Find out where's the end of line.
+        * Set parsenleft/parselleft acordingly.
+        * NUL chars are deleted.
+        */
        q = parsenextc;
-
-       /* delete nul characters */
        for (;;) {
-               int c;
+               char c;
 
                more--;
-               c = *q;
 
-               if (!c)
+               c = *q;
+               if (c == '\0') {
                        memmove(q, q + 1, more);
-               else {
+               } else {
                        q++;
                        if (c == '\n') {
                                parsenleft = q - parsenextc - 1;
@@ -9251,22 +9268,23 @@ preadbuffer(void)
        }
        parselleft = more;
 
-       savec = *q;
-       *q = '\0';
-
        if (vflag) {
+               char save = *q;
+               *q = '\0';
                out2str(parsenextc);
+               *q = save;
        }
 
-       *q = savec;
-
+       pgetc_debug("preadbuffer at %d:%p'%s'", parsenleft, parsenextc, parsenextc);
        return signed_char2int(*parsenextc++);
 }
 
 #define pgetc_as_macro() (--parsenleft >= 0 ? signed_char2int(*parsenextc++) : preadbuffer())
+
 static int
 pgetc(void)
 {
+       pgetc_debug("pgetc at %d:%p'%s'", parsenleft, parsenextc, parsenextc);
        return pgetc_as_macro();
 }
 
@@ -9325,11 +9343,9 @@ pfgets(char *line, int len)
 static void
 pungetc(void)
 {
-       /* check is needed for ash -c 'echo 5&' + BASH_COMPAT to work */
-       if (parsenleft < 0)
-               return;
        parsenleft++;
        parsenextc--;
+       pgetc_debug("pushed back to %d:%p'%s'", parsenleft, parsenextc, parsenextc);
 }
 
 /*
@@ -9343,16 +9359,17 @@ static void
 pushstring(char *s, struct alias *ap)
 {
        struct strpush *sp;
-       size_t len;
+       int len;
 
        len = strlen(s);
        INT_OFF;
        if (g_parsefile->strpush) {
-               sp = ckzalloc(sizeof(struct strpush));
+               sp = ckzalloc(sizeof(*sp));
                sp->prev = g_parsefile->strpush;
-               g_parsefile->strpush = sp;
-       } else
-               sp = g_parsefile->strpush = &(g_parsefile->basestrpush);
+       } else {
+               sp = &(g_parsefile->basestrpush);
+       }
+       g_parsefile->strpush = sp;
        sp->prevstring = parsenextc;
        sp->prevnleft = parsenleft;
 #if ENABLE_ASH_ALIAS
@@ -9442,7 +9459,7 @@ setinputfd(int fd, int push)
        close_on_exec_on(fd);
        if (push) {
                pushfile();
-               g_parsefile->buf = 0;
+               g_parsefile->buf = NULL;
        }
        g_parsefile->fd = fd;
        if (g_parsefile->buf == NULL)

diff --git a/shell/ash_test/ash-misc/last_amp.right b/shell/ash_test/ash-misc/last_amp.right
new file mode 100644 (file)
index 0000000..3da21ae
--- /dev/null
+++ b/shell/ash_test/ash-misc/last_amp.right
@@ -0,0 +1,2 @@
+3
+End

diff --git a/shell/ash_test/ash-misc/last_amp.tests b/shell/ash_test/ash-misc/last_amp.tests
new file mode 100755 (executable)
index 0000000..1609376
--- /dev/null
+++ b/shell/ash_test/ash-misc/last_amp.tests
@@ -0,0 +1,8 @@
+$THIS_SH -c 'echo 3&'
+d=`date`
+while test "`date`" = "$d"; do true; done
+d1=`date`
+$THIS_SH -c 'sleep 1&'
+d2=`date`
+test "$d1" = "$d2" || echo BAD
+echo End