[PATCH] strptime fixes

[PATCH] strptime fixes

[Julien Ramseier]

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I found several bugs in strptime:

1. tm_yday is off by one with %j (tm_yday range is 0-365 while %j is 1-366).
2. string pointer is not incremented when processing %p format.
3. calling strptime(..., "%C", tm), where tm->tm_year != 0, will result in a
   wrong value stored in tm_year.


[-- Attachment #2: strptime-%j-off-by-one.patch --]
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diff --git a/src/time/strptime.c b/src/time/strptime.c
index 55c7ed1..da9e1f4 100644
--- a/src/time/strptime.c
+++ b/src/time/strptime.c
@@ -73,6 +73,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			dest = &tm->tm_yday;
 			min = 1;
 			range = 366;
+			adj = 1;
 			goto numeric_range;
 		case 'm':
 			dest = &tm->tm_mon;

[-- Attachment #3: strptime-fix-%p-fmt.patch --]
[-- Type: application/octet-stream, Size: 613 bytes --]

diff --git a/src/time/strptime.c b/src/time/strptime.c
index da9e1f4..cff0a7c 100644
--- a/src/time/strptime.c
+++ b/src/time/strptime.c
@@ -94,6 +94,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			len = strlen(ex);
 			if (!strncasecmp(s, ex, len)) {
 				tm->tm_hour %= 12;
+				s += len;
 				break;
 			}
 			ex = nl_langinfo(PM_STR);
@@ -101,6 +102,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			if (!strncasecmp(s, ex, len)) {
 				tm->tm_hour %= 12;
 				tm->tm_hour += 12;
+				s += len;
 				break;
 			}
 			return 0;

[-- Attachment #4: strptime-fix-%C-fmt.patch --]
[-- Type: application/octet-stream, Size: 1018 bytes --]

diff --git a/src/time/strptime.c b/src/time/strptime.c
index cff0a7c..c54a0d8 100644
--- a/src/time/strptime.c
+++ b/src/time/strptime.c
@@ -11,7 +11,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 	int i, w, neg, adj, min, range, *dest, dummy;
 	const char *ex;
 	size_t len;
-	int want_century = 0, century = 0;
+	int want_century = 0, century = 0, relyear = 0;
 	while (*f) {
 		if (*f != '%') {
 			if (isspace(*f)) for (; *s && isspace(*s); s++);
@@ -144,7 +144,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			if (!s) return 0;
 			break;
 		case 'y':
-			dest = &tm->tm_year;
+			dest = &relyear;
 			w = 2;
 			want_century |= 1;
 			goto numeric_digits;
@@ -198,6 +198,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 		}
 	}
 	if (want_century) {
+		tm->tm_year = relyear;
 		if (want_century & 2) tm->tm_year += century * 100 - 1900;
 		else if (tm->tm_year <= 68) tm->tm_year += 100;
 	}

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- Julien

Re: [PATCH] strptime fixes

[Rich Felker]

On Sat, Mar 18, 2017 at 05:10:28PM +0100, Julien Ramseier wrote:
> I found several bugs in strptime:
> 
> 1. tm_yday is off by one with %j (tm_yday range is 0-365 while %j is 1-366).
> 2. string pointer is not incremented when processing %p format.
> 3. calling strptime(..., "%C", tm), where tm->tm_year != 0, will result in a
>    wrong value stored in tm_year.
> 

These all look fine, committing.

Rich