If we run test case present in JDK-8211422 it throws IIOException:
Exception in thread "main" javax.imageio.IIOException: Error reading PNG metadata
at java.desktop/com.sun.imageio.plugins.png.PNGImageReader.readMetadata(PNGImageReader.java:891)
at java.desktop/com.sun.imageio.plugins.png.PNGImageReader.readImage(PNGImageReader.java:1395)
at java.desktop/com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1810)
at ImageIObug.main(ImageIObug.java:22)
Caused by: javax.imageio.IIOException: Invalid chunk length 0
at java.desktop/com.sun.imageio.plugins.png.PNGImageReader.readMetadata(PNGImageReader.java:765)
... 3 more

This is happening because CRC for IEND chunk is not of length 4. Instead of just throwing an exception saying "Invalid chunk length 0" we should also say that CRC is not of length 4. chunk length 0 is valid for IEND chunk.