ContentSourceTransformer.read() may call release() more than once

[lorban]

Jetty version(s)
12.1.x

Description
After ContentSourceTransformer.fail(x, true) is called, each call to ContentSourceTransformer.read() calls ContentSourceTransformer.release().

If the implementation does not implement release() in an idempotent way, ContentSourceTransformer.read() may throw or misbehave.

How to reproduce?

Here is a test to be added to GzipDecoderSourceTest that illustrates the bug for GzipDecoderSource:

@ParameterizedTest
@MethodSource("textResources")
public void testTransformerBug(String textResourceName) throws Exception
{
    startGzip();
    String compressedName = String.format("%s.%s", textResourceName, gzip.getFileExtensionNames().get(0));
    Path compressed = MavenPaths.findTestResourceFile(compressedName);

    Content.Source fileSource = Content.Source.from(sizedPool, compressed);
    Content.Source decoderSource = gzip.newDecoderSource(fileSource);

    decoderSource.fail(new Throwable(), true);

    Content.Chunk chunk1 = decoderSource.read();
    Content.Chunk chunk2 = decoderSource.read();
    Content.Chunk chunk3 = decoderSource.read(); // this throws NPE
}

which fails with:

java.lang.NullPointerException: Inflater has been closed

	at java.base/java.util.zip.Inflater.ensureOpen(Inflater.java:714)
	at java.base/java.util.zip.Inflater.reset(Inflater.java:685)
	at [email protected]/org.eclipse.jetty.util.compression.InflaterPool.reset(InflaterPool.java:56)
	at [email protected]/org.eclipse.jetty.util.compression.InflaterPool.reset(InflaterPool.java:21)
	at [email protected]/org.eclipse.jetty.util.compression.CompressionPool$Entry.release(CompressionPool.java:142)
	at [email protected]/org.eclipse.jetty.compression.gzip.internal.GzipDecoderSource.release(GzipDecoderSource.java:277)
	at [email protected]/org.eclipse.jetty.io.content.ContentSourceTransformer.read(ContentSourceTransformer.java:77)
	at [email protected]/org.eclipse.jetty.compression.gzip.GzipDecoderSourceTest.testTransformerBug(GzipDecoderSourceTest.java:44)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)

[lorban]

See failures (search for NullPointerException in the standard error):

https://jenkins.webtide.net/job/jetty.project/job/jetty-12.1.x/473/testReport/junit/org.eclipse.jetty.ee11.proxy/AsyncMiddleManServletTest/Parallel_Stage___Build___Test___JDK17___testLargeChunkedGzippedBufferedDownstreamTransformation/

and

https://jenkins.webtide.net/job/jetty.project/job/jetty-12.1.x/473/testReport/junit/org.eclipse.jetty.ee8.proxy/AsyncMiddleManServletTest/Parallel_Stage___Build___Test___JDK17___testLargeChunkedGzippedBufferedDownstreamTransformation/

[lorban]

@joakime WDYT?

[joakime]

Yeah, seems like a bug in the release behavior.