[R] Possible solution for Mozilla/help.start() search problems

[Marc Schwartz]

I thought that I would post a follow up given the several posts on this
same subject in the past week. All R comments pertain to 1.6.1.

Earlier in the week using a development build of Mozilla under RH 8.0, I
was able to get the help.start() based search engine to work with both
Java and JavaScript enabled. This was using what I believed to be the
V1.2b branch of Mozilla, in which both Xft anti-aliasing font support
and Gtk2 support for RH 8.0 was included. There are RH 8.0 specific RPMS
located at:

http://komodo.mozilla.org/pub/mozilla/nightly/experimental/gtk2/

Upon verifying the version number however, this branch turns out to be
V1.3a of Mozilla, not 1.2b. At least this is what it is identifying 
itself as. The build that worked was dated 2002-11-18.
I post this for the sake of clarification.

Late tonight, I updated my Mozilla installation with the latest build
from the same branch, which is dated 2002-11-22.  Sure enough, the
help.start() search engine is non-functional with this build.

I spent some time tonight going back through and installing the several
builds from this past week and the build dated 2002-11-20 does not work
either.  Going back to the build from 2002-11-18 the search engine does 
work.

The only common observation that I had made is that in the versions
where the engine does not work, the browser status line message 
indicating that the Java applet has started, does not appear.  It does 
appear in the version from 2002-11-18, where the engine functions as 
expected. Thus it would seem that there is something intrinsic in the 
differing Mozilla versions that is inhibiting the R Java applet from 
properly loading and starting.

I spent some time tonight on both the Sun and Mozilla sites reviewing
FAQ's and Bugzilla and noted a variety of open Java related issues.

However, I did find one clue in the Mozilla 1.2b Release Notes that 
seems to have worked and I now have the help.start() search engine 
working in the 2002-11-22 Mozilla 1.3a build. The note would suggest 
that the browser may have problems locating the required Java modules to 
load and start the applet.

The fix seems to be to create (as root) a symlink to the file:

/usr/java/JAVA_VERSION/plugin/i386/ns610/libjavaplugin_oji.so

in your active Mozilla plugins directory.

In the process of doing this, I noted that there were multiple Moz* 
directories in /usr/lib, given the updating that I have done since 
installing RH 8.0. There was no symlink in usr/lib/Mozilla-1.3a/plugins.

Upon adding the symlink, lo and behold the help.start() search engine 
worked. If I remove the symlink, it fails.

Thus it is possible that as folks update Mozilla and Java installations 
and the respective directory structures change from version to version, 
this may cause a problem for Mozilla in properly locating the Java 
modules required to run the R search engine.

The pertinent release notes for Mozilla 1.2b are located at:

http://www.mozilla.org/releases/mozilla1.2b/#java

There are also comments there for Windows and similar comments are 
present in the release notes for earlier versions as well.

I though I would pass this on as a possible solution given the problems 
noted here of late.

HTH,

Marc Schwartz








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