<i18n dev> [PATCH FOR REVIEW] 6593486: RFE: support user-defined directory path to time zone data files

[Andrew John Hughes]

When distros update their timezone data, the data used by OpenJDK also
needs to be updated.  At present, this is difficult as OpenJDK uses a
hardcoded path (${java.home}/jre/lib/zi} for timezone data with no
option to override it.

A bug was filed for this issue back in 2007 and there was some
discussion on the mailing lists:

http://mail.openjdk.java.net/pipermail/i18n-dev/2007-August/000001.html

but no patch was committed.

I've updated the patch and provide a revised version in this webrev:

http://cr.openjdk.java.net/~andrew/6593486/webrev.01/jdk.patch

When the class is initialised, it attemps to read the property
sun.zoneinfo.dir from ${java.home}/jre/lib/tz.properties.  If it finds
a value, it checks that the file ${sun.zoneinfo.dir}/ZoneInfoMappings
exists as confirmation that this is indeed a directory of timezone
data.  If this or anything prior fails (no property, no tz.properties,
etc.) it will fall back to the current solution.  Thus, the new code
only has an effect if a tz.properties is added with the specified
property.

I confirmed this with strace.  With no tz.properties:

331   open("/mnt/builder/swing/j2sdk-image/jre/lib/tz.properties",
O_RDONLY) = -1 ENOENT (No such file or directory)
...
331   access("/mnt/builder/swing/j2sdk-image/jre/lib/zi/ZoneInfoMappings",
R_OK) = 0

With tz.properties containing 'sun.zoneinfo.dir=/usr/share/tzdata':

359   open("/mnt/builder/swing/j2sdk-image/jre/lib/tz.properties", O_RDONLY) = 4
359   fstat(4, {st_mode=S_IFREG|0644, st_size=35, ...}) = 0
359   fcntl(4, F_GETFD)                 = 0
359   fcntl(4, F_SETFD, FD_CLOEXEC)     = 0
359   lseek(3, 54661116, SEEK_SET)      = 54661116
359   read(3, "PK\3\4\n\0\0\0\0\0\26u\31;\"\372\336\250\264\7\0\0\264\7\0\0%\0\0\0"...,
30) = 30
359   lseek(3, 54661183, SEEK_SET)      = 54661183
359   read(3, "\312\376\272\276\0\0\0003\0K\t\0\16\0,\n\0\17\0-\t\0\16\0.\t\0\16\0/\t\0\16"...,
1972) = 1972
359   read(4, "sun.zoneinfo.dir=/usr/share/tzdat"..., 8192) = 35
359   fstat(4, {st_mode=S_IFREG|0644, st_size=35, ...}) = 0
359   lseek(4, 0, SEEK_CUR)             = 35
359   lseek(4, 0, SEEK_END)             = 35
359   lseek(4, 35, SEEK_SET)            = 35
359   read(4, ""..., 8192)              = 0
359   read(4, ""..., 8192)              = 0
359   close(4)                          = 0
359   stat("/usr/share/tzdata/ZoneInfoMappings", 0x7ff1cdcbe650)

The webrev is prepared against the swing forest as I was informed
earlier that the i18n forest is not in use.

Is it ok to commit this to swing-gate?

Thanks,
-- 
Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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