MFC r306075,r306109

1) Microoptimize %p case.
2) Implememt %u for GNU compatibility.
3) Don't forget to advance buf for %w/%u.
4) Fail with incomplete week (week 0) request and no such week in the
year.
5) Fix yday formula when Sunday requested and the week started from Monday.
6) Fail with impossible yday for incomplete week (week 0) and direct %w/%u
request.
7) Shift yday/wday to the first day of the year, if incomplete week
(week 0) requested and no %w/%u used.
8) For already non-standard %z extension implement GNU compatible formats:
+hh and -hh.
9) Check for incorrect values for %z.

PR:     212983 (case 3 only)

1 files changed, 32 insertions, 14 deletions

diff --git a/lib/libc/stdtime/strptime.c b/lib/libc/stdtime/strptime.c
index 2be6358..89703ec 100644
--- a/lib/libc/stdtime/strptime.c
+++ b/lib/libc/stdtime/strptime.c
@@ -301,10 +301,11 @@ label:
 			 * XXX This is bogus if parsed before hour-related
 			 * specifiers.
 			 */
+			if (tm->tm_hour > 12)
+				return (NULL);
+
 			len = strlen(tptr->am);
 			if (strncasecmp_l(buf, tptr->am, len, locale) == 0) {
-				if (tm->tm_hour > 12)
-					return (NULL);
 				if (tm->tm_hour == 12)
 					tm->tm_hour = 0;
 				buf += len;
@@ -313,8 +314,6 @@ label:
 
 			len = strlen(tptr->pm);
 			if (strncasecmp_l(buf, tptr->pm, len, locale) == 0) {
-				if (tm->tm_hour > 12)
-					return (NULL);
 				if (tm->tm_hour != 12)
 					tm->tm_hour += 12;
 				buf += len;
@@ -374,15 +373,17 @@ label:
 
 			break;
 
+		case 'u':
 		case 'w':
 			if (!isdigit_l((unsigned char)*buf, locale))
 				return (NULL);
 
-			i = *buf - '0';
-			if (i > 6)
+			i = *buf++ - '0';
+			if (i < 0 || i > 7 || (c == 'u' && i < 1) ||
+			    (c == 'w' && i > 6))
 				return (NULL);
 
-			tm->tm_wday = i;
+			tm->tm_wday = i % 7;
 			flags |= FLAG_WDAY;
 
 			break;
@@ -581,10 +582,16 @@ label:
 					i *= 10;
 					i += *buf - '0';
 					buf++;
+				} else if (len == 2) {
+					i *= 100;
+					break;
 				} else
 					return (NULL);
 			}
 
+			if (i > 1400 || (sign == -1 && i > 1200) ||
+			    (i % 100) >= 60)
+				return (NULL);
 			tm->tm_hour -= sign * (i / 100);
 			tm->tm_min  -= sign * (i % 100);
 			*GMTp = 1;
@@ -609,17 +616,28 @@ label:
 			    TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
 			flags |= FLAG_YDAY;
 		} else if (day_offset != -1) {
+			int tmpwday, tmpyday, fwo;
+
+			fwo = first_wday_of(tm->tm_year + TM_YEAR_BASE);
+			/* No incomplete week (week 0). */
+			if (week_offset == 0 && fwo == day_offset)
+				return (NULL);
+
 			/* Set the date to the first Sunday (or Monday)
 			 * of the specified week of the year.
 			 */
-			if (!(flags & FLAG_WDAY)) {
-				tm->tm_wday = day_offset;
-				flags |= FLAG_WDAY;
+			tmpwday = (flags & FLAG_WDAY) ? tm->tm_wday :
+			    day_offset;
+			tmpyday = (7 - fwo + day_offset) % 7 +
+			    (week_offset - 1) * 7 +
+			    (tmpwday - day_offset + 7) % 7;
+			/* Impossible yday for incomplete week (week 0). */
+			if (tmpyday < 0) {
+				if (flags & FLAG_WDAY)
+					return (NULL);
+				tmpyday = 0;
 			}
-			tm->tm_yday = (7 -
-			    first_wday_of(tm->tm_year + TM_YEAR_BASE) +
-			    day_offset) % 7 + (week_offset - 1) * 7 +
-			    tm->tm_wday - day_offset;
+			tm->tm_yday = tmpyday;
 			flags |= FLAG_YDAY;
 		}
 	}