>Number: 754
>Category: general
>Synopsis: GMT timestamps sometimes falsely claim to be PDT
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: apache (Apache HTTP Project)
>State: open
>Class: sw-bug
>Submitter-Id: apache
>Arrival-Date: Thu Jun 19 11:40:00 1997
>Originator: [EMAIL PROTECTED]
>Organization:
apache
>Release: 1.2
>Environment:
SunOS shade 5.5.1 Generic_103640-08 sun4u sparc SUNW,Ultra-1
GCC snapshot 961108
>Description:
ht_time passes the output of gmtime to strftime, but on hosts where
struct tm does not include a time zone name or offset, strftime must
assume that its argument is local time, not GMT. This causes strftime
to mishandle %Z formats (and %z formats, on hosts that support this
extension). In particular, the DATE_GMT setting will be bogus.
>How-To-Repeat:
Using a debugger, invoke
ht_time(anything, 0, "%Z", 1)
under Solaris 2.5.1. The result will say "PDT or "PST" (if in Pacific time);
it should say "GMT".
>Fix:
Here's a patch.
===================================================================
RCS file: src/util.c,v
retrieving revision 1.2
retrieving revision 1.2.0.1
diff -c -r1.2 -r1.2.0.1
*** src/util.c 1997/04/12 04:24:59 1.2
--- src/util.c 1997/06/19 18:26:15 1.2.0.1
***************
*** 77,86 ****
--- 77,121 ----
char *ht_time(pool *p, time_t t, const char *fmt, int gmt) {
char ts[MAX_STRING_LEN];
+ char tf[MAX_STRING_LEN];
struct tm *tms;
tms = (gmt ? gmtime(&t) : localtime(&t));
+ if(gmt) {
+ /* Convert %Z to "GMT" and %z to "+0000";
+ * on hosts that do not have a time zone string in struct tm,
+ * strftime must assume its argument is local time.
+ */
+ const char *f;
+ char *p;
+ for(p = tf, f = fmt; p < tf + sizeof tf - 5 && (*p = *f); f++, p++) {
+ if(*f == '%')
+ switch(f[1])
+ {
+ case '%':
+ *++p = *++f;
+ break;
+ case 'Z':
+ *p++ = 'G';
+ *p++ = 'M';
+ *p = 'T';
+ f++;
+ break;
+ case 'z': /* common extension */
+ *p++ = '+';
+ *p++ = '0';
+ *p++ = '0';
+ *p++ = '0';
+ *p = '0';
+ f++;
+ break;
+ }
+ }
+ *p = '\0';
+ fmt = tf;
+ }
+
/* check return code? */
strftime(ts,MAX_STRING_LEN,fmt,tms);
return pstrdup (p, ts);
%0
>Audit-Trail:
>Unformatted:
