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Bug 362140

Summary:	Print a null variable throws eglx.lang.NullValueException
Product:	z_Archived	Reporter:	fahua jin <jinfahua>
Component:	EDT	Assignee:	Jeff Douglas <jeffdouglas>
Status:	CLOSED FIXED	QA Contact:
Severity:	normal
Priority:	P1	CC:	carrollk, jqian, svihovec
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description fahua jin

2011-10-26 20:54:46 EDT

Build Identifier: 0.7.0.v201110241434

Create a program, and copy following two lines of EGL code to the main function.

--------------------------
times timeStamp?;
syslib.writeStdout(times);
--------------------------

Following exception will be thrown when running the program.

A null value was used.
eglx.lang.NullValueException A null value was used.
	at eglx.lang.AnyException.fillInStackTrace(AnyException.java:187)
	at java.lang.Throwable.<init>(Throwable.java:181)
	at java.lang.Exception.<init>(Exception.java:29)
	at java.lang.RuntimeException.<init>(RuntimeException.java:32)
	at eglx.lang.AnyException.<init>(AnyException.java:32)
	at eglx.lang.NullValueException.<init>(NullValueException.java:17)
	at org.eclipse.edt.javart.util.JavartUtil.checkNullable(JavartUtil.java:243)
	at server.PrimitiveNotInitPrg.main(PrimitiveNotInitPrg.java:33)
	at org.eclipse.edt.javart.resources.RunUnitBase.start(RunUnitBase.java:244)
	at server.PrimitiveNotInitPrg.main(PrimitiveNotInitPrg.java:18)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.edt.javart.ide.MainProgramLauncher.main(MainProgramLauncher.java:68)


I don't think simply print the null object should throw the exception. I made another test - if use this statement "syslib.writeStdout(null);", then the console print an empty line. It looks to me that the behavior of the same syntax have is different.


Reproducible: Always

Comment 1 fahua jin

2011-10-26 20:55:21 EDT

Brian, could you please advise on this?

Comment 2 Brian Svihovec

2011-10-27 13:49:59 EDT

I talked with Matt about this defect, and he pointed out that the signature for writestdout is:

static function writeStdout(text string in);

This means that passing a null value to this function would be the equivalent of doing an assignment of that null value to a temporary variable of type "string".  

This can also be tested using the following example:

function main()
		var1 String;
		//var1 = null; Compile Error
		var2 Timestamp?;
		var1 = var2;
		
	end

If you run the program above, you get the same exception as listed in the initial Description for this defect.  This means that passing 'times' to writestdout is working correctly.  During our discussion, we also determined that passing Null to writestdout should throw the same exception.  

NOTE: There should already be a defect opened for producing a better error message.

I have subscribed Jing as well, since the test group will need to verify that this behavior is the same on Java and JavaScript.

Comment 3 Jing Qian

2011-10-27 14:22:15 EDT

Kathy will add this into the EUnit tests as part of null testing. 

- pass in the literal null
- pass in the null variable

Comment 4 Jeff Douglas

2011-10-27 17:17:06 EDT

Fixed. A NullValueException will now be throw on writestdout and writestderr.

Comment 5 Jing Qian

2011-10-27 21:41:58 EDT

Jeff, I hope this means anywhere a string is used, not just writestdout and writestderr.

Comment 6 fahua jin

2011-10-28 01:42:00 EDT

Verified in 0.7.0.v201110272101 for the test scenario in this defect.