created an attachment (id=169279)
screenshot

description:
exception is thrown out when run chart-viewer-sample and the tube chart & pie chart are not shown.

build number:
2.6.0.v20100520-0630

steps to reproduce:
1. deploy chart-viewer-sample on tomcat 5.5.23.
2. run "http://host:port/chart-viewer-sample"

expected result:
no exception.

actual result:
exception is thrown out (see the screenshot).
error log:
org.eclipse.birt.chart.exception.chartexception
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.generat
estream(unknown source)
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.generat
eimage(unknown source)
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.<init>(
unknown source)
        at org.eclipse.birt.chart.viewer.internal.chartrenderertag.doendtag(unkn
own source)
        at org.apache.jsp.index_jsp._jspservice(index_jsp.java:99)
        at org.apache.jasper.runtime.httpjspbase.service(httpjspbase.java:98)
        at javax.servlet.http.httpservlet.service(httpservlet.java:803)
        at org.apache.jasper.servlet.jspservletwrapper.service(jspservletwrapper
.java:328)
        at org.apache.jasper.servlet.jspservlet.servicejspfile(jspservlet.java:3
15)
        at org.apache.jasper.servlet.jspservlet.service(jspservlet.java:265)
        at javax.servlet.http.httpservlet.service(httpservlet.java:803)
        at org.apache.catalina.core.applicationfilterchain.internaldofilter(appl
icationfilterchain.java:269)
        at org.apache.catalina.core.applicationfilterchain.dofilter(applicationf
ilterchain.java:188)
        at org.apache.catalina.core.standardwrappervalve.invoke(standardwrapperv
alve.java:210)
        at org.apache.catalina.core.standardcontextvalve.invoke(standardcontextv
alve.java:174)
        at org.apache.catalina.core.standardhostvalve.invoke(standardhostvalve.j
ava:127)
        at org.apache.catalina.valves.errorreportvalve.invoke(errorreportvalve.j
ava:117)
        at org.apache.catalina.core.standardenginevalve.invoke(standardengineval
ve.java:108)
        at org.apache.catalina.connector.coyoteadapter.service(coyoteadapter.jav
a:151)
        at org.apache.coyote.http11.http11processor.process(http11processor.java
:870)
        at org.apache.coyote.http11.http11baseprotocol$http11connectionhandler.p
rocessconnection(http11baseprotocol.java:665)
        at org.apache.tomcat.util.net.pooltcpendpoint.processsocket(pooltcpendpo
int.java:528)
        at org.apache.tomcat.util.net.leaderfollowerworkerthread.runit(leaderfol
lowerworkerthread.java:81)
        at org.apache.tomcat.util.threads.threadpool$controlrunnable.run(threadp
ool.java:685)
        at java.lang.thread.run(thread.java:619)
caused by: java.lang.nullpointerexception
        at org.eclipse.birt.chart.factory.generator.preparestyles(generator.java
:141)
        at org.eclipse.birt.chart.factory.generator.build(generator.java:1006)
        ... 25 more
org.eclipse.birt.chart.exception.chartexception
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.generat
estream(unknown source)
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.generat
eimage(unknown source)
        at org.eclipse.birt.chart.viewer.internal.util.chartimagemanager.<init>(
unknown source)
        at org.eclipse.birt.chart.viewer.internal.chartrenderertag.doendtag(unkn
own source)
        at org.apache.jsp.index_jsp._jspx_meth_chart_005frenderchart_005f2(index
_jsp.java:203)
        at org.apache.jsp.index_jsp._jspservice(index_jsp.java:154)
        at org.apache.jasper.runtime.httpjspbase.service(httpjspbase.java:98)
        at javax.servlet.http.httpservlet.service(httpservlet.java:803)
        at org.apache.jasper.servlet.jspservletwrapper.service(jspservletwrapper
.java:328)
        at org.apache.jasper.servlet.jspservlet.servicejspfile(jspservlet.java:3
15)
        at org.apache.jasper.servlet.jspservlet.service(jspservlet.java:265)
        at javax.servlet.http.httpservlet.service(httpservlet.java:803)
        at org.apache.catalina.core.applicationfilterchain.internaldofilter(appl
icationfilterchain.java:269)
        at org.apache.catalina.core.applicationfilterchain.dofilter(applicationf
ilterchain.java:188)
        at org.apache.catalina.core.standardwrappervalve.invoke(standardwrapperv
alve.java:210)
        at org.apache.catalina.core.standardcontextvalve.invoke(standardcontextv
alve.java:174)
        at org.apache.catalina.core.standardhostvalve.invoke(standardhostvalve.j
ava:127)
        at org.apache.catalina.valves.errorreportvalve.invoke(errorreportvalve.j
ava:117)
        at org.apache.catalina.core.standardenginevalve.invoke(standardengineval
ve.java:108)
        at org.apache.catalina.connector.coyoteadapter.service(coyoteadapter.jav
a:151)
        at org.apache.coyote.http11.http11processor.process(http11processor.java
:870)
        at org.apache.coyote.http11.http11baseprotocol$http11connectionhandler.p
rocessconnection(http11baseprotocol.java:665)
        at org.apache.tomcat.util.net.pooltcpendpoint.processsocket(pooltcpendpo
int.java:528)
        at org.apache.tomcat.util.net.leaderfollowerworkerthread.runit(leaderfol
lowerworkerthread.java:81)
        at org.apache.tomcat.util.threads.threadpool$controlrunnable.run(threadp
ool.java:685)
        at java.lang.thread.run(thread.java:619)
caused by: java.lang.nullpointerexception
        at org.eclipse.birt.chart.factory.generator.preparestyles(generator.java
:141)
        at org.eclipse.birt.chart.factory.generator.build(generator.java:1006)
        ... 26 more
already fixed npe.
verified in build (2.6.0.v20100521-0630), closed.