Patch to expand tz checking scope in TimeZone_md.c

[Jonathan Lu]

Hi Masayoshi,

I did find some references about date-time related functions / TZ 
variables on Linux but got only a few about Solaris, so could not see 
any differences between those two platforms about the changes described 
in my patch. Have you got any links or references about these 
differences? I'm interested in it and may update the patch again after 
reading them.

Thanks a lot!
- Jonathan

On 11/02/2011 10:27 PM, Masayoshi Okutsu wrote:
> Hi Jonathan,
>
> IIRC, the difference came from some behavioral difference between the 
> Linux and Solaris libc date-time functions and/or the date command, 
> and TimeZone_md.c tries to follow the difference. But the code was 
> written looooong ago. The difference may no longer exist.
>
> Thanks,
> Masayoshi
>
> On 11/2/2011 8:39 PM, Jonathan Lu wrote:
>> On 11/02/2011 07:00 PM, David Holmes wrote:
>>> On 2/11/2011 7:01 PM, Jonathan Lu wrote:
>>>> On 11/02/2011 04:56 PM, Jonathan Lu wrote:
>>>>> Hi core-libs-dev,
>>>>>
>>>>> In jdk/src/solaris/native/java/util/TimeZone_md.c, starting from line
>>>>> 626, I found that the scope of "#ifdef __solaris__" might be too
>>>>> narrow, since it also works for some kind of OS which I'm currently
>>>>> working on, such as AIX.
>>>>> So I suggest to just remove the '#ifdef __solaris__' and leave the
>>>>> "#else" to accommodate more conditions, see attachment 
>>>>> 'patch.diff'. I
>>>>> think this may enhance the cross-platform ability, any ideas about
>>>>> this modification?
>>>>>
>>>>> Regards
>>>>> - Jonathan Lu
>>>> I'm not sure why the attachment got filtered, here paste it to the 
>>>> mail
>>>> content directly.
>>>>
>>>> diff -r 4788745572ef src/solaris/native/java/util/TimeZone_md.c
>>>> --- a/src/solaris/native/java/util/TimeZone_md.c Mon Oct 17 19:06:53
>>>> 2011 -0700
>>>> +++ b/src/solaris/native/java/util/TimeZone_md.c Thu Oct 20 13:43:47
>>>> 2011 +0800
>>>> @@ -626,10 +626,8 @@
>>>> #ifdef __linux__
>>>> if (tz == NULL) {
>>>> #else
>>>> -#ifdef __solaris__
>>>> if (tz == NULL || *tz == '\0') {
>>>> #endif
>>>> -#endif
>>>> tz = getPlatformTimeZoneID();
>>>> freetz = tz;
>>>> }
>>>
>>> I'm unclear why any of that code needs to be platform specific - is 
>>> an empty TZ string somehow valid on linux? I would have thought the 
>>> following would be platform neutral:
>>>
>>>    if (tz == NULL || *tz == '\0') {
>>>         tz = getPlatformTimeZoneID();
>>>         freetz = tz;
>>>     }
>>>
>> Hi David,
>>
>> getenv("TZ") returns NULL when TZ environment variable is not set at 
>> all and returns '\0' when TZ was exported as empty string. After more 
>> checking for both cases, I agree with you, nothing useful can be 
>> retrieved from that environment variable.
>> So I changed the patch to this,
>>
>> diff -r 7ab0d613cd1a src/solaris/native/java/util/TimeZone_md.c
>> --- a/src/solaris/native/java/util/TimeZone_md.c    Thu Oct 20 
>> 10:32:47 2011 -0700
>> +++ b/src/solaris/native/java/util/TimeZone_md.c    Wed Nov 02 
>> 19:34:51 2011 +0800
>> @@ -623,13 +623,7 @@
>>
>>      tz = getenv("TZ");
>>
>> -#ifdef __linux__
>> -    if (tz == NULL) {
>> -#else
>> -#ifdef __solaris__
>>      if (tz == NULL || *tz == '\0') {
>> -#endif
>> -#endif
>>          tz = getPlatformTimeZoneID();
>>          freetz = tz;
>>      }
>>
>>> David
>>> -----
>>>
>>>> Regards
>>>> - Jonathan Lu
>> Regards
>>
>> - Jonathan
>>