UI: characters lost / hidden / swallowed at end of line in edit window, by the vertical slider? Small problem but confusing.

[newbie-02]

I experience that at the end of some lines touching the right window border
the last character is not or only partly displayed, see attached screenshot
row 2: ... dass das deutliche (n) and near bottom in the green circle:
'Redesignin (g)'
here the hidden characters are partly visible, often they are totally off,
and in consequence the editor has to check against 'false positive typos'.

[edit] Another assumption for the source of problem:
someone forgot to account the space used for the vertical slider?
The issue isn't active for very short texts not needing a slider.
It pops up when the text exceeds the window size and AsciidocFX
adds the slider. [/edit]

Assume confusion between zero-based vs. one based counting.
Evtl. the log from terminal window attached at bottom may help in debugging.

java.nio.charset.CoderMalfunctionError: java.lang.IllegalArgumentException: newPosition < 0: (10 < 0)
        at java.base/java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:588)
        at morfologik.stemming.BufferUtils.charsToBytes(BufferUtils.java:161)
        at morfologik.speller.Speller.charSequenceToBytes(Speller.java:189)
        at morfologik.speller.Speller.isInDictionary(Speller.java:253)
        at morfologik.speller.Speller.isMisspelled(Speller.java:233)
        at com.kodedu.spell.dictionary.LanguageSpeller.isMisspelled(LanguageSpeller.java:26)
        at com.kodedu.spell.dictionary.DictionaryService.lambda$processTokens$1(DictionaryService.java:88)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:178)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
        at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
        at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
        at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
        at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
        at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
        at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
        at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
        at com.kodedu.spell.dictionary.DictionaryService.processTokens(DictionaryService.java:103)
        at com.kodedu.controller.ApplicationController.lambda$processTokens$206(ApplicationController.java:2612)
        at com.kodedu.service.impl.ThreadServiceImpl$1.call(ThreadServiceImpl.java:53)
        at javafx.graphics@21/javafx.concurrent.Task$TaskCallable.call(Task.java:1399)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:572)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
        at java.base/java.lang.VirtualThread.run(VirtualThread.java:311)
Caused by: java.lang.IllegalArgumentException: newPosition < 0: (10 < 0)
        at java.base/java.nio.Buffer.createPositionException(Buffer.java:352)
        at java.base/java.nio.Buffer.position(Buffer.java:327)
        at java.base/java.nio.ByteBuffer.position(ByteBuffer.java:1551)
        at java.base/java.nio.ByteBuffer.position(ByteBuffer.java:285)
        at java.base/sun.nio.cs.UTF_8.updatePositions(UTF_8.java:83)
        at java.base/sun.nio.cs.UTF_8$Encoder.encodeArrayLoopSlow(UTF_8.java:509)
        at java.base/sun.nio.cs.UTF_8$Encoder.encodeArrayLoop(UTF_8.java:461)
        at java.base/sun.nio.cs.UTF_8$Encoder.encodeLoop(UTF_8.java:564)
        at java.base/java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:586)
        ... 25 more
30976461 [] INFO  c.k.e.AsciidocAsciidoctorjConverter - Converted Asciidoc to HTML5 
30981386 [] INFO  c.k.e.AsciidocAsciidoctorjConverter - Converted Asciidoc to HTML5 
`

[rahmanusta]

I'm not able to reproduce it. I would like to test if you share with me some document

[rahmanusta]

Can you share some photos?

[rahmanusta]

The issue mentioned was resolved for the editor window. However, I don’t notice the issue about preview

[smowton]

In case this has not become clear in the interim, the exception posted at the top featuring the nonsensical complaint newPosition < 0: (10 < 0) indicates illegal concurrent calls to this CharsetEncoder instance by multiple threads. Looking at the source code for Buffer at https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/nio/Buffer.java#L326 we can see the test newPosition > limit | newPosition < 0 fails, where newPosition is 10, but then on constructing the failure report finds that in fact 10 is within the now-changed limit and assumes it must be negative.

As noted at https://docs.oracle.com/javase/7/docs/api/java/nio/charset/CharsetEncoder.html, instances of CharsetEncoder must not be used by multiple concurrent threads.

I found this thread because I just finished troubleshooting the same problem, and this is the only google hit for "CoderMalfunctionError" "newPosition < 0" :D