Reading comment comments after Root Element closed sometimes throws NullPointerException

[GuoHuiChen]

TextBuffer.recycle()
206 char[] buf = mCurrentSegment;
207 mCurrentSegment = null;
this.mHasSegments = false; //MUST set false
208 mConfig.freeMediumCBuffer(buf);

284 if (mHasSegments) {
clearSegments();

1050 char[] curr = mCurrentSegment;
1051 int max = curr.length - mCurrentSize; //NPE

[GuoHuiChen]

430016_NG0405_20180720_V01.zip
This is the sample XML.

Exception in thread "main" java.lang.NullPointerException
at com.ctc.wstx.util.TextBuffer.append(TextBuffer.java:1050)
at com.ctc.wstx.util.TextBuffer.resetWithCopy(TextBuffer.java:291)
at com.ctc.wstx.sr.BasicStreamReader.readComment(BasicStreamReader.java:3908)
at com.ctc.wstx.sr.BasicStreamReader.finishToken(BasicStreamReader.java:3808)
at com.ctc.wstx.sr.BasicStreamReader.safeFinishToken(BasicStreamReader.java:3741)
at com.ctc.wstx.sr.BasicStreamReader.getText(BasicStreamReader.java:889)

[GuoHuiChen]

Please fix this bug, Thank you!

[cowtowncoder]

@GuoHuiChen Thank you for reporting the problem.

I tried simplest code I can do that creates XMLStreamReader for test file, but I did not get exception.
So I would like to know what is different with your usage. Could you add code you are using for reading the contents? Or something to trigger the exception.

[GuoHuiChen]

Thank you for your response. @cowtowncoder (url)
TestReadCommentAfterRoot.zip

Put the 430016_NG0405_20180720_V01.xml in C:\temp directory.
run the test

Exception in thread "main" java.lang.NullPointerException
at com.ctc.wstx.util.TextBuffer.append(TextBuffer.java:1051)
at com.ctc.wstx.util.TextBuffer.resetWithCopy(TextBuffer.java:292)
at com.ctc.wstx.sr.BasicStreamReader.readComment(BasicStreamReader.java:3843)
at com.ctc.wstx.sr.BasicStreamReader.finishToken(BasicStreamReader.java:3743)
at com.ctc.wstx.sr.BasicStreamReader.safeFinishToken(BasicStreamReader.java:3676)
at com.ctc.wstx.sr.BasicStreamReader.getText(BasicStreamReader.java:860)
at TestReadCommentAfterRoot.test(TestReadCommentAfterRoot.java:50)
at TestReadCommentAfterRoot.main(TestReadCommentAfterRoot.java:64)

[GuoHuiChen]

Please fix this bug!

[cowtowncoder]

@GuoHuiChen At this point I will not have much time to work on OSS, and when I do, I will have to think carefully what to work on. Comments asking for speedy work will not help, and sometimes may even put the issue on bottom of the stack.

[cowtowncoder]

I am able to reproduce the issue, hope to solve today -- thank you for reporting this.
The issue is that the underlying buffer is released on main xml tree closing, but then needing it to access COMMENT (or PROCESSING_INSTRUCTION) content. So need to figure out best way to avoid the problem; either by not releasing buffer as early, or, possibly, verifying is it is reallocated as needed.

[cowtowncoder]

Fixed, will release 5.3.0 later today.