Fix issue resizing bin/sh

This partially reverts some changes from r237448 that are causing
breakage when resizing under bin/sh .

Reverted changes from NetBSD are:

Mar 10 20:46:15 2009 - editline.3 read.c
make el_gets set the count to -1 on error to distinguish between EOF and
error.

Feb 19 15:20:22 2009 - read.c sig.c sig.h
reset and redraw on sigcont. From Anon Ymous.

Feb 15 21:24:13 2009
don't restart on EINTR, instead return NULL immediately. From Anon Ymous

PR:		169603
Reported by:	Peter Jeremy, David Shao
MFC after:	3 days

lib/libedit/editline.3

@@ -162,11 +162,6 @@ is modified to contain the number of characters read.
 Returns the line read if successful, or
 .Dv NULL
 if no characters were read or if an error occurred.
-If an error occurred,
-.Fa count
-is set to \-1 and
-.Dv errno
-contains the error code that caused it.
 The return value may not remain valid across calls to
 .Fn el_gets
 and must be copied if the data is to be retained.

lib/libedit/el.h

@@ -115,7 +115,6 @@ struct editline {
 	FILE		 *el_errfile;	/* Stdio stuff			*/
 	int		  el_infd;	/* Input file descriptor	*/
 	int		  el_flags;	/* Various flags.		*/
-	int		  el_errno;	/* Local copy of errno		*/
 	coord_t		  el_cursor;	/* Cursor location		*/
 	char		**el_display;	/* Real screen image = what is there */
 	char		**el_vdisplay;	/* Virtual screen image = what we see */

lib/libedit/read.c

@@ -49,7 +49,7 @@ __FBSDID("$FreeBSD$");
 #include <stdlib.h>
 #include "el.h"
 
-#define	OKCMD	-1	/* must be -1! */
+#define	OKCMD	-1
 
 private int	read__fixio(int, int);
 private int	read_preread(EditLine *);
@@ -170,7 +170,7 @@ read__fixio(int fd __unused, int e)
 		return (e ? 0 : -1);
 
 	case EINTR:
-		return (-1);
+		return (0);
 
 	default:
 		return (-1);
@@ -235,12 +235,9 @@ read_getcmd(EditLine *el, el_action_t *cmdnum, char *ch)
 	el_action_t cmd;
 	int num;
 
-	el->el_errno = 0;
 	do {
-		if ((num = el_getc(el, ch)) != 1) {	/* if EOF or error */
-			el->el_errno = num == 0 ? 0 : errno;
+		if ((num = el_getc(el, ch)) != 1)	/* if EOF or error */
 			return (num);
-		}
 
 #ifdef	KANJI
 		if ((*ch & 0200)) {
@@ -292,21 +289,14 @@ read_char(EditLine *el, char *cp)
 	ssize_t num_read;
 	int tried = 0;
 
- again:
-	el->el_signal->sig_no = 0;
-	while ((num_read = read(el->el_infd, cp, 1)) == -1) {
-		if (el->el_signal->sig_no == SIGCONT) {
-			sig_set(el);
-			el_set(el, EL_REFRESH);
-			goto again;
-		}
+	while ((num_read = read(el->el_infd, cp, 1)) == -1)
 		if (!tried && read__fixio(el->el_infd, errno) == 0)
 			tried = 1;
 		else {
 			*cp = '\0';
 			return (-1);
 		}
-	}
+
 	return (int)num_read;
 }
 
@@ -413,20 +403,17 @@ el_gets(EditLine *el, int *nread)
 	int num;		/* how many chars we have read at NL */
 	char ch;
 	int crlf = 0;
-	int nrb;
 #ifdef FIONREAD
 	c_macro_t *ma = &el->el_chared.c_macro;
 #endif /* FIONREAD */
 
-	if (nread == NULL)
-		nread = &nrb;
 	*nread = 0;
 
 	if (el->el_flags & NO_TTY) {
 		char *cp = el->el_line.buffer;
 		size_t idx;
 
-		while ((num = (*el->el_read.read_char)(el, cp)) == 1) {
+		while ((*el->el_read.read_char)(el, cp) == 1) {
 			/* make sure there is space for next character */
 			if (cp + 1 >= el->el_line.limit) {
 				idx = (cp - el->el_line.buffer);
@@ -440,16 +427,12 @@ el_gets(EditLine *el, int *nread)
 			if (cp[-1] == '\r' || cp[-1] == '\n')
 				break;
 		}
-		if (num == -1) {
-			if (errno == EINTR)
-				cp = el->el_line.buffer;
-			el->el_errno = errno;
-		}
 
 		el->el_line.cursor = el->el_line.lastchar = cp;
 		*cp = '\0';
-		*nread = (int)(el->el_line.cursor - el->el_line.buffer);
-		goto done;
+		if (nread)
+			*nread = (int)(el->el_line.cursor - el->el_line.buffer);
+		return (*nread ? el->el_line.buffer : NULL);
 	}
 
 
@@ -460,8 +443,8 @@ el_gets(EditLine *el, int *nread)
 		(void) ioctl(el->el_infd, FIONREAD, (ioctl_t) & chrs);
 		if (chrs == 0) {
 			if (tty_rawmode(el) < 0) {
-				errno = 0;
-				*nread = 0;
+				if (nread)
+					*nread = 0;
 				return (NULL);
 			}
 		}
@@ -474,7 +457,6 @@ el_gets(EditLine *el, int *nread)
 	if (el->el_flags & EDIT_DISABLED) {
 		char *cp;
 		size_t idx;
-
 		if ((el->el_flags & UNBUFFERED) == 0)
 			cp = el->el_line.buffer;
 		else
@@ -482,7 +464,7 @@ el_gets(EditLine *el, int *nread)
 
 		term__flush(el);
 
-		while ((num = (*el->el_read.read_char)(el, cp)) == 1) {
+		while ((*el->el_read.read_char)(el, cp) == 1) {
 			/* make sure there is space next character */
 			if (cp + 1 >= el->el_line.limit) {
 				idx = (cp - el->el_line.buffer);
@@ -498,15 +480,11 @@ el_gets(EditLine *el, int *nread)
 				break;
 		}
 
-		if (num == -1) {
-			if (errno == EINTR)
-				cp = el->el_line.buffer;
-			el->el_errno = errno;
-		}
-
 		el->el_line.cursor = el->el_line.lastchar = cp;
 		*cp = '\0';
-		goto done;
+		if (nread)
+			*nread = (int)(el->el_line.cursor - el->el_line.buffer);
+		return (*nread ? el->el_line.buffer : NULL);
 	}
 
 	for (num = OKCMD; num == OKCMD;) {	/* while still editing this
@@ -522,12 +500,6 @@ el_gets(EditLine *el, int *nread)
 #endif /* DEBUG_READ */
 			break;
 		}
-		if (el->el_errno == EINTR) {
-			el->el_line.buffer[0] = '\0';
-			el->el_line.lastchar =
-			    el->el_line.cursor = el->el_line.buffer;
-			break;
-		}
 		if ((unsigned int)cmdnum >= (unsigned int)el->el_map.nfunc) {	/* BUG CHECK command */
 #ifdef DEBUG_EDIT
 			(void) fprintf(el->el_errfile,
@@ -645,17 +617,12 @@ el_gets(EditLine *el, int *nread)
 	/* make sure the tty is set up correctly */
 	if ((el->el_flags & UNBUFFERED) == 0) {
 		read_finish(el);
-		*nread = num != -1 ? num : 0;
+		if (nread)
+			*nread = num;
 	} else {
-		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
+		if (nread)
+			*nread =
+			    (int)(el->el_line.lastchar - el->el_line.buffer);
 	}
-done:
-	if (*nread == 0) {
-		if (num == -1) {
-			*nread = -1;
-			errno = el->el_errno;
-		}
-		return NULL;
-	} else
-		return el->el_line.buffer;
+	return (num ? el->el_line.buffer : NULL);
 }

lib/libedit/sig.c

@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$NetBSD: sig.c,v 1.15 2009/02/19 15:20:22 christos Exp $
+ *	$NetBSD: sig.c,v 1.14 2009/02/18 15:04:40 christos Exp $
  */
 
 #if !defined(lint) && !defined(SCCSID)
@@ -73,8 +73,6 @@ sig_handler(int signo)
 	(void) sigaddset(&nset, signo);
 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
 
-	sel->el_signal->sig_no = signo;
-
 	switch (signo) {
 	case SIGCONT:
 		tty_rawmode(sel);
@@ -160,12 +158,12 @@ sig_set(EditLine *el)
 	struct sigaction osa, nsa;
 
 	nsa.sa_handler = sig_handler;
-	nsa.sa_flags = 0;
 	sigemptyset(&nsa.sa_mask);
 
 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
 
 	for (i = 0; sighdl[i] != -1; i++) {
+		nsa.sa_flags = SIGINT ? 0 : SA_RESTART;
 		/* This could happen if we get interrupted */
 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
 		    osa.sa_handler != sig_handler)

lib/libedit/sig.h

@@ -30,7 +30,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)sig.h	8.1 (Berkeley) 6/4/93
- *	$NetBSD: sig.h,v 1.5 2003/08/07 16:44:33 agc Exp $
+ *	$NetBSD: sig.h,v 1.7 2009/02/15 21:25:01 christos Exp $
  * $FreeBSD$
  */
 
@@ -61,7 +61,6 @@
 typedef struct {
 	struct sigaction sig_action[ALLSIGSNO];
 	sigset_t sig_set;
-	volatile sig_atomic_t sig_no;
 } *el_signal_t;
 
 protected void	sig_end(EditLine*);