Sun Jun 18 22:27:25 2006  Arnold D. Robbins  <arnold@skeeve.com>

    Repair internal names like /dev/user, /dev/pid, as well as /dev/fd/N,
    which have been broken for a long time but noone noticed.

    * io.c (is_internal): new macro to check for internal file like `/dev/user'.
    (spec_setup): Reduce to two parameters, allocate logic is always true.
    Add IOP_NO_FREE to flag.
    (pidopen, useropen): Return `IOBUF *' instead of int. Fix
    logic to test if `iop' parameter is NULL and if so to allocate it.
    (specfdopen,): Return `IOBUF *' instead of int. Fix
    logic to test if `iop' parameter is NULL and if so to allocate it.
    Don't set IOP_NO_FREE in flag.
    (iop_open): Remove `IOBUF iob' field from `struct internal' and its use
    and the use of `spec_setup' from the code here. Change the check in the
    call to the open function to look for NULL.
    (get_a_record): Use `is_internal' in initial check for filling the
    buffer to not try to call `read' on internal files. If true, set
    the IOP_AT_EOF in the flag and return EOF.

--- gawk-3.1.5/io.c.internal	2006-06-21 19:46:59.000000000 +0200
+++ gawk-3.1.5/io.c	2006-06-21 19:49:54.000000000 +0200
@@ -110,6 +110,7 @@
 #define at_eof(iop)     ((iop->flag & IOP_AT_EOF) != 0)
 #define has_no_data(iop)        (iop->dataend == NULL)
 #define no_data_left(iop)	(iop->off >= iop->dataend)
+#define is_internal(iop) ((iop->flag & IOP_IS_INTERNAL) != 0)
 /* The key point to the design is to split out the code that searches through */
 /* a buffer looking for the record and the terminator into separate routines, */
 /* with a higher-level routine doing the reading of data and buffer management. */
@@ -163,10 +164,10 @@
 static int gawk_pclose P((struct redirect *rp));
 static int do_pathopen P((const char *file));
 static int str2mode P((const char *mode));
-static void spec_setup P((IOBUF *iop, int len, int allocate));
-static int specfdopen P((IOBUF *iop, const char *name, const char *mode));
-static int pidopen P((IOBUF *iop, const char *name, const char *mode));
-static int useropen P((IOBUF *iop, const char *name, const char *mode));
+static void spec_setup P((IOBUF *iop, int len));
+static IOBUF *specfdopen P((IOBUF *iop, const char *name, const char *mode));
+static IOBUF *pidopen P((IOBUF *iop, const char *name, const char *mode));
+static IOBUF *useropen P((IOBUF *iop, const char *name, const char *mode));
 static int two_way_open P((const char *str, struct redirect *rp));
 static int pty_vs_pipe P((const char *command));
 
@@ -1422,30 +1423,24 @@
 /* spec_setup --- setup an IOBUF for a special internal file */
 
 static void
-spec_setup(IOBUF *iop, int len, int allocate)
+spec_setup(IOBUF *iop, int len)
 {
 	char *cp;
 
-	if (allocate) {
-		emalloc(cp, char *, len+2, "spec_setup");
-		iop->buf = cp;
-	} else {
-		len = strlen(iop->buf);
-		iop->buf[len++] = '\n';	/* get_a_record clobbered it */
-		iop->buf[len] = '\0';	/* just in case */
-	}
+	emalloc(cp, char *, len+2, "spec_setup");
+	iop->buf = cp;
 	iop->off = iop->buf;
 	iop->count = 0;
 	iop->size = len;
 	iop->end = iop->buf + len;
 	iop->dataend = iop->end;
 	iop->fd = -1;
-	iop->flag = IOP_IS_INTERNAL | IOP_AT_START;
+	iop->flag = IOP_IS_INTERNAL | IOP_AT_START | IOP_NO_FREE;
 }
 
 /* specfdopen --- open an fd special file */
 
-static int
+static IOBUF *
 specfdopen(IOBUF *iop, const char *name, const char *mode)
 {
 	int fd;
@@ -1453,23 +1448,20 @@
 
 	fd = devopen(name, mode);
 	if (fd == INVALID_HANDLE)
-		return INVALID_HANDLE;
-	tp = iop_alloc(fd, name, NULL);
+		return NULL;
+	tp = iop_alloc(fd, name, iop);
 	if (tp == NULL) {
 		/* don't leak fd's */
 		close(fd);
-		return INVALID_HANDLE;
+		return NULL;
 	}
-	*iop = *tp;
-	iop->flag |= IOP_NO_FREE;
-	free(tp);
-	return 0;
+	return tp;
 }
 
 
 /* pidopen --- "open" /dev/pid, /dev/ppid, and /dev/pgrpid */
 
-static int
+static IOBUF *
 pidopen(IOBUF *iop, const char *name, const char *mode ATTRIBUTE_UNUSED)
 {
 	char tbuf[BUFSIZ];
@@ -1478,6 +1470,12 @@
 
 	warning(_("use `PROCINFO[\"%s\"]' instead of `%s'"), cp, name);
 
+	if (iop == NULL) {
+		iop = iop_alloc(INVALID_HANDLE, name, iop);
+		if (iop == NULL)
+			return NULL;
+	}
+
 	if (name[6] == 'g')
 #ifdef GETPGRP_VOID
 		sprintf(tbuf, "%d\n", (int) getpgrp());
@@ -1489,9 +1487,9 @@
 	else
 		sprintf(tbuf, "%d\n", (int) getppid());
 	i = strlen(tbuf);
-	spec_setup(iop, i, TRUE);
+	spec_setup(iop, i);
 	strcpy(iop->buf, tbuf);
-	return 0;
+	return iop;
 }
 
 /* useropen --- "open" /dev/user */
@@ -1506,7 +1504,7 @@
  * supplementary group set.
  */
 
-static int
+static IOBUF *
 useropen(IOBUF *iop, const char *name ATTRIBUTE_UNUSED, const char *mode ATTRIBUTE_UNUSED)
 {
 	char tbuf[BUFSIZ], *cp;
@@ -1514,6 +1512,12 @@
 
 	warning(_("use `PROCINFO[...]' instead of `/dev/user'"));
 
+	if (iop == NULL) {
+		iop = iop_alloc(INVALID_HANDLE, name, iop);
+		if (iop == NULL)
+			return NULL;
+	}
+
 	sprintf(tbuf, "%d %d %d %d", (int) getuid(), (int) geteuid(), (int) getgid(), (int) getegid());
 
 	cp = tbuf + strlen(tbuf);
@@ -1528,9 +1532,9 @@
 	*cp++ = '\0';
 
 	i = strlen(tbuf);
-	spec_setup(iop, i, TRUE);
+	spec_setup(iop, i);
 	strcpy(iop->buf, tbuf);
-	return 0;
+	return iop;
 }
 
 /* iop_open --- handle special and regular files for input */
@@ -1543,8 +1547,7 @@
 	static struct internal {
 		const char *name;
 		int compare;
-		int (*fp) P((IOBUF *, const char *, const char *));
-		IOBUF iob;
+		IOBUF *(*fp) P((IOBUF *, const char *, const char *));
 	} table[] = {
 		{ "/dev/fd/",		8,	specfdopen },
 		{ "/dev/stdin",		10,	specfdopen },
@@ -1569,12 +1572,7 @@
 
 		for (i = 0; i < devcount; i++) {
 			if (STREQN(name, table[i].name, table[i].compare)) {
-				iop = & table[i].iob;
-
-				if (iop->buf != NULL) {
-					spec_setup(iop, 0, FALSE);
-					return iop;
-				} else if ((*table[i].fp)(iop, name, mode) == 0)
+				if ((iop = (*table[i].fp)(iop, name, mode)) != NULL)
 					return iop;
 				else {
 					warning(_("could not open `%s', mode `%s'"),
@@ -2909,6 +2907,10 @@
 
         /* <fill initial buffer>=                                                   */
         if (has_no_data(iop) || no_data_left(iop)) {
+		if (is_internal(iop)) {
+			iop->flag |= IOP_AT_EOF;
+			return EOF;
+		}
                 iop->count = read(iop->fd, iop->buf, iop->readsize);
                 if (iop->count == 0) {
                         iop->flag |= IOP_AT_EOF;