[JDK-8210527] NullPointerException in jstack exception rendering

[Robert Field]

Fix out for review.

-Robert


On 8/20/19 5:07 PM, Stuart Marks wrote:
> The jshell mailing list is kulla-dev at openjdk.java.net. I'm cc'ing that 
> list and bcc'ing jdk-dev. (Yes, the name "kulla-dev" is quite opaque. 
> Sorry.)
>
> s'marks
>
> On 8/19/19 1:10 PM, Steven Schlansker wrote:
>> Hello jdk-dev, (hopefully this is the best list, I did not see a 
>> jshell-dev)
>>
>> I spent most of my Friday diagnosing a confusing issue
>> https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8229863
>>
>> which turned out to be a duplicate of JDK-8210527
>> Unfortunately it's been open most of a year with no progress.
>>
>> The fix is seemingly trivial:
>>
>> diff -r 31b7274c7b9e src/jdk.jshell/share/classes/jdk/jshell/Eval.java
>> --- a/src/jdk.jshell/share/classes/jdk/jshell/Eval.java Fri Aug 09 
>> 03:36:59 2019 +0200
>> +++ b/src/jdk.jshell/share/classes/jdk/jshell/Eval.java Mon Aug 19 
>> 13:06:57 2019 -0700
>> @@ -1106,7 +1106,7 @@
>>                   Snippet sn = outer.wrapLineToSnippet(wln);
>>                   String file = "#" + sn.id();
>>                   elems[i] = new StackTraceElement(klass, method, 
>> file, line);
>> -            } else if (r.getFileName().equals("<none>")) {
>> +            } else if ("<none>".equals(r.getFileName())) {
>>                   elems[i] = new StackTraceElement(r.getClassName(), 
>> r.getMethodName(), null, r.getLineNumber());
>>               } else {
>>                   elems[i] = r;
>>
>> I verified this fix against jdk13 tip.  Before:
>>
>> Unexpected exception reading startup: java.lang.NullPointerException
>> java.lang.NullPointerException
>>     at 
>> jdk.jshell/jdk.jshell.Eval.translateExceptionStack(Eval.java:1109)
>>     at jdk.jshell/jdk.jshell.Eval.asEvalException(Eval.java:907)
>>     at jdk.jshell/jdk.jshell.Eval.declare(Eval.java:888)
>>     at jdk.jshell/jdk.jshell.Eval.eval(Eval.java:140)
>>     at jdk.jshell/jdk.jshell.JShell.eval(JShell.java:493)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.processSource(JShellTool.java:3558)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.processSourceCatchingReset(JShellTool.java:1305)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.processInput(JShellTool.java:1203)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.run(JShellTool.java:1176)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.startUpRun(JShellTool.java:1143)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.resetState(JShellTool.java:1099)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellTool.start(JShellTool.java:933)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellToolBuilder.start(JShellToolBuilder.java:254)
>>     at 
>> jdk.jshell/jdk.internal.jshell.tool.JShellToolProvider.run(JShellToolProvider.java:94)
>>     at JshellNpe.main(JshellNpe.java:20)
>>
>> After,
>>
>> Exception java.lang.IllegalStateException: This helpful exception 
>> message is lost
>>        at JshellNpe.lambda$2 (JshellNpe.java:27)
>>        at $Proxy0.hashCode (Unknown Source)
>>        at JshellNpe.init (JshellNpe.java:28)
>>        at (#s1:1)
>>
>> Much better!
>>
>> What can I do to help move this issue forward to resolution?
>>
>> thanks,
>> Steven
>>