Consume one leading space with %e iff given

Since strftime(3)'s %e conversion specification preceeds single digits by a
blank, do the converse here to allow safe data round trips through these
functions with the same format string.

Positive feedback tedu deraadt,
OK millert jca

2 files changed, 10 insertions, 7 deletions

diff --git a/lib/libc/time/strptime.3 b/lib/libc/time/strptime.3
index 8872a8e7aaf..ed667de4f96 100644
--- a/lib/libc/time/strptime.3
+++ b/lib/libc/time/strptime.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: strptime.3,v 1.26 2019/01/21 21:35:58 tedu Exp $
+.\"	$OpenBSD: strptime.3,v 1.27 2019/02/21 19:10:32 kn Exp $
 .\"
 .\" Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -26,7 +26,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: January 21 2019 $
+.Dd $Mdocdate: February 21 2019 $
 .Dt STRPTIME 3
 .Os
 .Sh NAME
@@ -96,8 +96,8 @@ leading zeros are permitted but not required.
 .It Cm \&%D
 the date as %m/%d/%y.
 .It Cm \&%e
-the same as
-.Cm \&%d .
+the day of month [1,31];
+leading spaces or zeros are permitted but not required.
 .It Cm \&%F
 the date as %Y-%m-%d
 (the
diff --git a/lib/libc/time/strptime.c b/lib/libc/time/strptime.c
index 01330b20d4b..eaf182dc773 100644
--- a/lib/libc/time/strptime.c
+++ b/lib/libc/time/strptime.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: strptime.c,v 1.24 2019/01/22 11:09:03 cheloha Exp $ */
+/*	$OpenBSD: strptime.c,v 1.25 2019/02/21 19:10:32 kn Exp $ */
 /*	$NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $	*/
 /*-
  * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
@@ -254,8 +254,11 @@ literal:
 			century = i * 100;
 			break;
 
-		case 'd':	/* The day of month. */
-		case 'e':
+		case 'e':	/* The day of month. */
+			if (isspace(*bp))
+				bp++;
+			/* FALLTHROUGH */
+		case 'd':
 			_LEGAL_ALT(_ALT_O);
 			if (!(_conv_num(&bp, &tm->tm_mday, 1, 31)))
 				return (NULL);