Re:[PATCH] tzset did not catch changes tolocaltime [BZ #21060 ]

[<ma dot jiang at zte dot com dot cn>]

Hi schwab,
  Thanks for the quick reply.
  I have changed the patch into the following one, as you suggested.   Is it OK now?

diff --git a/time/tzset.c b/time/tzset.c
index b517867..1431097 100644
--- a/time/tzset.c
+++ b/time/tzset.c
@@ -386,22 +386,27 @@ tzset_internal (int always)
   if (tz && *tz == ':')
     ++tz;

-  /* Check whether the value changed since the last run.  */
-  if (old_tz != NULL && tz != NULL && strcmp (tz, old_tz) == 0)
-    /* No change, simply return.  */
-    return;
-
   if (tz == NULL)
     /* No user specification; use the site-wide default.  */
     tz = TZDEFAULT;

+  /* Check whether the tz value changed since the last run.  */
+  bool tz_changed = (old_tz == NULL) || (strcmp (tz, old_tz) != 0);
+  if (old_tz == NULL || tz_changed)
+    {
+      /* Save the value of `tz'. */
+      free (old_tz);
+      old_tz = __strdup (tz);
+    }
+  
+  /* When using tzfile, must check whether it changed in  __tzfile_read.  */
+  if (!__use_tzfile && !tz_changed)
+    return;
+
+  /* Going to recaculate values. */
   tz_rules[0].name = NULL;
   tz_rules[1].name = NULL;

-  /* Save the value of `tz'.  */
-  free (old_tz);
-  old_tz = tz ? __strdup (tz) : NULL;
-
   /* Try to read a data file.  */
   __tzfile_read (tz, 0, NULL);
   if (__use_tzfile)




------------------原始邮件------------------
发件人：AndreasSchwab <schwab@suse.de>
收件人：马江10100629;
抄送人：carlos@redhat.com <carlos@redhat.com>;libc-alpha@sourceware.org <libc-alpha@sourceware.org>;
日 期 ：2018年12月17日 17:40
主 题 ：Re: [PATCH]   tzset did not catch changes tolocaltime  [BZ #21060 ]
On Dez 17 2018, <ma.jiang@zte.com.cn> wrote:

> +  /* Check whether the tz value changed since the last run.  */
> +  int tz_changed = old_tz ? strcmp (tz, old_tz) : 1;

This should be written as old_tz == NULL || strcmp (tz, old_tz) != 0,
and tz_changed should be bool.

> +  if ((old_tz == NULL)
> +      || (old_tz != NULL && tz_changed))

This is the same as tz_changed.

> +  {
> +    /* Save the value of `tz'. */
> +    free (old_tz);
> +    old_tz = __strdup (tz);
> +  }

Wrong indentation.

Andreas.

--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
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