commit a548d383b230b02d1ca0fc44acc384a32d82abac
Author: Steffen Daode Nurpmeso <sdaoden@gmail.com>
Date:   2012-09-10 15:39:00 +0200

    Add a new EL_READRESTART option for editline(3)
    
    Which makes it possible to realize read(2) restarts after EINTR
    errors without actually going the expensive (and sometimes
    impossible) way through signal handling.
    
    Unfortunately editline(3) doesn't offer anything like
    "el_gets_continue()", which could be used to simply restart the
    last editing session at the point where it ended, and it seems
    much harder to add that functionality (also in respect to merging
    in between *BSD versions) than to add this flag.

diff --git a/lib/libedit/editline.3 b/lib/libedit/editline.3
index 1f26b39..7bb783e 100644
--- a/lib/libedit/editline.3
+++ b/lib/libedit/editline.3
@@ -388,6 +388,22 @@ check this
 (using
 .Fn el_get )
 to determine if editing should be enabled or not.
+.It Dv EL_READRESTART , Fa "int flag"
+If
+.Fa flag
+is zero (the default),
+then
+.Fn el_getc
+and
+.Fn el_gets
+will not treat
+.Dv EINTR
+errors any special and automatically restart reading characters.
+Note this may be restricted to the builtin character read function
+.Dv EL_BUILTIN_GETCFN
+(see
+.Dv EL_GETCFN
+below).
 .It Dv EL_UNBUFFERED , Fa "int flag"
 If
 .Fa flag
@@ -498,6 +514,9 @@ Retrieve
 previously registered with the corresponding
 .Fn el_set
 call.
+.It Dv EL_READRESTART , Fa "int"
+Return non-zero if reading of characters is restarted after signal
+interruption.
 .It Dv EL_UNBUFFERED , Fa "int"
 Return non-zero if unbuffered mode is enabled.
 .It Dv EL_PREP_TERM , Fa "int"
diff --git a/lib/libedit/el.c b/lib/libedit/el.c
index d6cfb2d..4be765f 100644
--- a/lib/libedit/el.c
+++ b/lib/libedit/el.c
@@ -274,6 +274,13 @@ el_set(EditLine *el, int op, ...)
 		el->el_data = va_arg(ap, void *);
 		break;
 
+	case EL_READRESTART:
+		if (va_arg(ap, int))
+			el->el_flags |= READRESTART;
+		else
+			el->el_flags &= ~READRESTART;
+		break;
+
 	case EL_UNBUFFERED:
 		rv = va_arg(ap, int);
 		if (rv && !(el->el_flags & UNBUFFERED)) {
@@ -435,6 +442,11 @@ el_get(EditLine *el, int op, ...)
 		rv = 0;
 		break;
 
+	case EL_READRESTART:
+		*va_arg(ap, int *) = (el->el_flags & READRESTART) != 0;
+		rv = 0;
+		break;
+
 	case EL_UNBUFFERED:
 		*va_arg(ap, int *) = (!(el->el_flags & UNBUFFERED));
 		rv = 0;
diff --git a/lib/libedit/el.h b/lib/libedit/el.h
index 67d01ff..d1321cc 100644
--- a/lib/libedit/el.h
+++ b/lib/libedit/el.h
@@ -54,7 +54,8 @@
 #define	HANDLE_SIGNALS	0x01
 #define	NO_TTY		0x02
 #define	EDIT_DISABLED	0x04
-#define	UNBUFFERED	0x08
+#define	READRESTART	0x08
+#define	UNBUFFERED	0x10
 
 typedef int bool_t;			/* True or not			*/
 
diff --git a/lib/libedit/histedit.h b/lib/libedit/histedit.h
index 8a6caf9..13d0cbf 100644
--- a/lib/libedit/histedit.h
+++ b/lib/libedit/histedit.h
@@ -130,15 +130,16 @@ unsigned char	_el_fn_sh_complete(EditLine *, int);
 #define	EL_RPROMPT	12	/* , el_pfunc_t);		*/
 #define	EL_GETCFN	13	/* , el_rfunc_t);		*/
 #define	EL_CLIENTDATA	14	/* , void *);			*/
-#define	EL_UNBUFFERED	15	/* , int);			*/
-#define	EL_PREP_TERM    16	/* , int);                      */
-#define	EL_GETTC	17	/* , const char *, ..., NULL);	*/
-#define	EL_GETFP	18	/* , int, FILE **);		*/
-#define	EL_SETFP	19	/* , int, FILE *);		*/
-#define	EL_REFRESH	20	/* , void);			      set     */
-#define	EL_PROMPT_ESC	21	/* , prompt_func, Char);	      set/get */
-#define	EL_RPROMPT_ESC	22	/* , prompt_func, Char);	      set/get */
-#define	EL_RESIZE	23	/* , el_zfunc_t, void *);	      set     */
+#define	EL_READRESTART	15	/* , int);			*/
+#define	EL_UNBUFFERED	16	/* , int);			*/
+#define	EL_PREP_TERM    17	/* , int);                      */
+#define	EL_GETTC	18	/* , const char *, ..., NULL);	*/
+#define	EL_GETFP	19	/* , int, FILE **);		*/
+#define	EL_SETFP	20	/* , int, FILE *);		*/
+#define	EL_REFRESH	21	/* , void);			      set     */
+#define	EL_PROMPT_ESC	22	/* , prompt_func, Char);	      set/get */
+#define	EL_RPROMPT_ESC	23	/* , prompt_func, Char);	      set/get */
+#define	EL_RESIZE	24	/* , el_zfunc_t, void *);	      set     */
 
 #define	EL_BUILTIN_GETCFN	(NULL)
 
diff --git a/lib/libedit/read.c b/lib/libedit/read.c
index ecd1ee2..3634d7e 100644
--- a/lib/libedit/read.c
+++ b/lib/libedit/read.c
@@ -300,6 +300,8 @@ read_char(EditLine *el, char *cp)
 			el_set(el, EL_REFRESH);
 			goto again;
 		}
+		if (e == EINTR && (el->el_flags & READRESTART))
+			goto again;
 		if (!tried && read__fixio(el->el_infd, e) == 0)
 			tried = 1;
 		else {