CauseParameterInExceptionCheck: ArrayIndexOutOfBoundsException

[rnveach]

Identified at #571 (comment) , and was able to reproduce with the latest version of checkstyle in report http://rveach.no-ip.org/checkstyle/regression/reports/61/apache-ant/index.html#A4

Got an exception - java.lang.ArrayIndexOutOfBoundsException: 586
at com.puppycrawl.tools.checkstyle.api.AbstractCheck.log(AbstractCheck.java:253)
at com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter.log(AbstractViolationReporter.java:144)
at com.github.sevntu.checkstyle.checks.design.CauseParameterInExceptionCheck.finishTree(CauseParameterInExceptionCheck.java:174)

Exception is happening because the field exceptionClassesToWarn isn't being cleared when processing multiple files when an exception is thrown on the previous file's run. The problem is only surfacing because of haltOnException being off.
finishTree shouldn't be used to reset instance fields. It is not guaranteed to always be called, like on an exception.

Here is the source of the checkstyle-result.xml:

<file name="/home/ricky/opensource/contribution/checkstyle-tester/reports/saverefs/apache-ant/src/main/org/apache/tools/ant/taskdefs/optional/ejb/IPlanetEjbc.java">
<error line="0" severity="error" message="Got an exception - java.lang.NullPointerException&#10;	at com.github.sevntu.checkstyle.checks.coding.NoNullForCollectionReturnCheck.getMethodDef(NoNullForCollectionReturnCheck.java:355)&#10;	at com.github.sevntu.checkstyle.checks.coding.NoNullForCollectionReturnCheck.visitToken(NoNullForCollectionReturnCheck.java:147)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.notifyVisit(TreeWalker.java:363)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.processIter(TreeWalker.java:500)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.walk(TreeWalker.java:305)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.processFiltered(TreeWalker.java:180)&#10;	at com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck.process(AbstractFileSetCheck.java:78)&#10;	at com.puppycrawl.tools.checkstyle.Checker.processFile(Checker.java:316)&#10;	at com.puppycrawl.tools.checkstyle.Checker.processFiles(Checker.java:286)&#10;	at com.puppycrawl.tools.checkstyle.Checker.process(Checker.java:213)&#10;	at org.apache.maven.plugin.checkstyle.exec.DefaultCheckstyleExecutor.executeCheckstyle(DefaultCheckstyleExecutor.java:252)&#10;	at org.apache.maven.plugin.checkstyle.AbstractCheckstyleReport.executeReport(AbstractCheckstyleReport.java:473)&#10;	at org.apache.maven.plugin.checkstyle.CheckstyleReport.executeReport(CheckstyleReport.java:154)&#10;	at org.apache.maven.reporting.AbstractMavenReport.generate(AbstractMavenReport.java:255)&#10;	at org.apache.maven.plugins.site.ReportDocumentRenderer.renderDocument(ReportDocumentRenderer.java:219)&#10;	at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.renderModule(DefaultSiteRenderer.java:319)&#10;	at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.render(DefaultSiteRenderer.java:135)&#10;	at org.apache.maven.plugins.site.SiteMojo.renderLocale(SiteMojo.java:175)&#10;	at org.apache.maven.plugins.site.SiteMojo.execute(SiteMojo.java:138)&#10;	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)&#10;	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)&#10;	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)&#10;	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)&#10;	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)&#10;	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)&#10;	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)&#10;	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)&#10;	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)&#10;	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)&#10;	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)&#10;	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)&#10;	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)&#10;	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)&#10;	at java.lang.reflect.Method.invoke(Method.java:498)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)&#10;" source="com.puppycrawl.tools.checkstyle.Checker"/>
</file>
<file name="/home/ricky/opensource/contribution/checkstyle-tester/reports/saverefs/apache-ant/src/main/org/apache/tools/ant/taskdefs/optional/ejb/DescriptorHandler.java">
<error line="0" severity="error" message="Got an exception - java.lang.ArrayIndexOutOfBoundsException: 586&#10;	at com.puppycrawl.tools.checkstyle.api.AbstractCheck.log(AbstractCheck.java:253)&#10;	at com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter.log(AbstractViolationReporter.java:144)&#10;	at com.github.sevntu.checkstyle.checks.design.CauseParameterInExceptionCheck.finishTree(CauseParameterInExceptionCheck.java:174)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.notifyEnd(TreeWalker.java:349)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.walk(TreeWalker.java:307)&#10;	at com.puppycrawl.tools.checkstyle.TreeWalker.processFiltered(TreeWalker.java:180)&#10;	at com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck.process(AbstractFileSetCheck.java:78)&#10;	at com.puppycrawl.tools.checkstyle.Checker.processFile(Checker.java:316)&#10;	at com.puppycrawl.tools.checkstyle.Checker.processFiles(Checker.java:286)&#10;	at com.puppycrawl.tools.checkstyle.Checker.process(Checker.java:213)&#10;	at org.apache.maven.plugin.checkstyle.exec.DefaultCheckstyleExecutor.executeCheckstyle(DefaultCheckstyleExecutor.java:252)&#10;	at org.apache.maven.plugin.checkstyle.AbstractCheckstyleReport.executeReport(AbstractCheckstyleReport.java:473)&#10;	at org.apache.maven.plugin.checkstyle.CheckstyleReport.executeReport(CheckstyleReport.java:154)&#10;	at org.apache.maven.reporting.AbstractMavenReport.generate(AbstractMavenReport.java:255)&#10;	at org.apache.maven.plugins.site.ReportDocumentRenderer.renderDocument(ReportDocumentRenderer.java:219)&#10;	at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.renderModule(DefaultSiteRenderer.java:319)&#10;	at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.render(DefaultSiteRenderer.java:135)&#10;	at org.apache.maven.plugins.site.SiteMojo.renderLocale(SiteMojo.java:175)&#10;	at org.apache.maven.plugins.site.SiteMojo.execute(SiteMojo.java:138)&#10;	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)&#10;	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)&#10;	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)&#10;	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)&#10;	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)&#10;	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)&#10;	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)&#10;	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)&#10;	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)&#10;	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)&#10;	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)&#10;	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)&#10;	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)&#10;	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)&#10;	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)&#10;	at java.lang.reflect.Method.invoke(Method.java:498)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)&#10;	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)&#10;" source="com.puppycrawl.tools.checkstyle.Checker"/>
</file>

Reports don't show file's order of execution, only the XML result file does.
Previous file's exception was an NPE in NoNullForCollectionReturnCheck when processing IPlanetEjbc.java.
Once it was fixed, ArrayIndexOutOfBoundsException disappeared from reports.

[romani]

fix is merged