Jackson encoder releases resources in wrong order #30493
Description
Affects: 5.2.10+, 5.3.0+
Ran into the following issue while using AbstractJackson2Encoder and the jackson csv serializer:
java.lang.NullPointerException: null at com.fasterxml.jackson.core.util.ByteArrayBuilder.write(ByteArrayBuilder.java:245) ~[jackson-core-2.13.5.jar:2.13.5] at com.fasterxml.jackson.dataformat.csv.impl.UTF8Writer.close(UTF8Writer.java:62) ~[jackson-dataformat-csv-2.13.5.jar:2.13.5] at com.fasterxml.jackson.dataformat.csv.impl.CsvEncoder.close(CsvEncoder.java:994) ~[jackson-dataformat-csv-2.13.5.jar:2.13.5] at com.fasterxml.jackson.dataformat.csv.CsvGenerator.close(CsvGenerator.java:503) ~[jackson-dataformat-csv-2.13.5.jar:2.13.5] at org.springframework.http.codec.json.AbstractJackson2Encoder.lambda$encode$2(AbstractJackson2Encoder.java:173) ~[spring-web-5.3.27.jar:5.3.27] The problem is the optimization in commit 7bee3d1 after calling byteBuilder.release() it should not be used, but if generator has its own buffers then generator.close() can trigger a flush to the byteBuilder.
It should be fixable by reordering the operations so byteBuilder is released last.
This probably also means the generator needs to be flushed and checked whether there is a trailing DataBuffer that still needs to be sent before terminating the stream. (concatWith(if generator.flush() != [], DataBuffer))