Differences between OpenJDK 8u and IcedTea8

[Severin Gehwolf]

Hi Volker,

On Thu, 2020-01-09 at 17:36 +0100, Volker Simonis wrote:
> Hi Severin,
> 
> thanks for the quick reply.
> 
> On Thu, Jan 9, 2020 at 1:32 PM Severin Gehwolf <sgehwolf at redhat.com> wrote:
> > Hi Volker,
> > 
> > On Thu, 2020-01-09 at 12:11 +0100, Volker Simonis wrote:
> > > Hi,
> > > 
> > > I've just realized that ojk8u-dev currently doesn't build correctly if
> > > configured with "--with-zlib=system".
> > 
> > Could you be more specific? What's working (if any) and what's broken
> > exactly? Is it this?
> > 
> > https://icedtea.classpath.org/bugzilla/show_bug.cgi?id=1413
> > 
> 
> Yes, it's exactly that one. I have included a link to the patch [2] in
> my previous mail:
> 
> [2] http://icedtea.classpath.org//hg/icedtea8-forest/jdk?cmd=changeset;node=c5b4565befea
> 
> > > This was surprising to me,
> > > because I know that most  (all?) Linux distributions link their ojdk8
> > > packages dynamically against the system provided libz (and I could
> > > verify this on my Ubuntu machine).
> > > 
> > > So I took a peek at the IcedTea 8 repo [1] and found that this issue
> > > was fixed there since a long time ago [2]. I was also surprised to see
> > > that the IcedTea 8 jdk repository actually contains quite some fixes
> > > and downports which are not in OpenJDK 8u yet [3] (e.g. HiDPI
> > > support).
> > > 
> > > Now that Red Hat is leading the OpenJDK 8 updates project, is there
> > > any specific reason (except the lack of time :)) why you still keep
> > > these changes in IcedTea instead of pushing them upstream to
> > > jdk8u-dev?
> > 
> > Yes.
> > 
> > We don't use the IcedTea 8 tree for the Red Hat OpenJDK builds.
> > Although, I know some other distros use it. We use [1] plus some
> > patches. No IcedTea per se involved. We want to stay as close to
> > upstream as possible. Feel free to have a look at the SRPM if you're
> > interested.
> > 
> 
> That's interesting, although it doesn't really simplify the situation
> (at least not for me :). So why are the IcedTea 8 repos then still
> kept up to date?

It's open source. Anyone can pick it up/maintain and use it :) AFAIK,
Andrew Hughes is mostly working on it in his spare time.

> > "--with-zlib-system" works for us[2]. I haven't investigated why it
> > doesn't work for you.
> > 
> 
> Well "--with-zlib=system", definitely doesn't work for the plain
> http://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah. It also
> doesn't work for the plain OpenJDK sources contained in the source rpm
> I've downloaded from [1]. I realized that the source rpm contains a
> set of additional patches but I couldn't easily apply them manually.
> Nevertheless I greped through them and they don't seem to contain  the
> mentioned fix for PR1423 [2].

My quick reading of the bug suggested it wasn't reproducible
everywhere. Could this be an Ubuntu/SUSE specific thing?

> So maybe the fix finally gets into the
> sources somehow magically in a way I don't understand, but the
> question remains, why such trivial fixes don't get up-streamed?

Not sure about that. I think it's mostly a matter of somebody-will-
have-to-spend-time-to-get-it-upstream question like you mentioned
earlier.

Thanks,
Severin

> [1] https://kojipkgs.fedoraproject.org//packages/java-1.8.0-openjdk/1.8.0.242.b04/0.0.ea.fc32/src/java-1.8.0-openjdk-1.8.0.242.b04-0.0.ea.fc32.src.rpm
> [2] https://icedtea.classpath.org/bugzilla/show_bug.cgi?id=1413
> 
> > Thanks,
> > Severin
> > 
> > [1] http://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/
> > [2] For example: https://src.fedoraproject.org/rpms/java-1.8.0-openjdk/blob/master/f/java-1.8.0-openjdk.spec#_1659
> > 
> > > Thank you and best regards,
> > > Volker
> > > 
> > > [1]  http://icedtea.classpath.org/hg/icedtea8-forest/jdk
> > > [2] http://icedtea.classpath.org//hg/icedtea8-forest/jdk?cmd=changeset;node=c5b4565befea
> > > [3] http://icedtea.classpath.org/hg/icedtea8-forest/jdk/search/?rev=PR1&revcount=100
> > >