LGTM. We're all resisting the urge to modernize this test. On Fri, Feb 28, 2020 at 5:17 AM Volker Simonis <volker.simo...@gmail.com> wrote:
> Hi, > > can I please get a review for this trivial test fix: > > http://cr.openjdk.java.net/~simonis/webrevs/2020/8240226/ > https://bugs.openjdk.java.net/browse/JDK-8240226 > > The SkipBytes() subtest in DeflateIn_InflateOut.java executes several > steps and for each step it deflates an array of 1024*1024 bytes. In > every step, before deflation is performed, the array is refilled with > random bytes. However, only after the first step, the size of the > generated, deflated stream is checked and recorded. The following > subtests all assume that deflating the array filled with the same > number of, but different, random bytes will produce a deflated stream > of the same size. > > This assumption is wrong. Depending on the exact contents of the > source array, the size of the generated, deflated result might > slightly differ. For some reason, the deflated result produced by the > default zlib implementation seems to always have the same size > (although there's no guarantee for this), but other zlib > implementations sometimes produce differently sized, deflated results. > > The problem can easily be reproduced by placing a version of > Cloudflare's zlib clone (https://github.com/cloudflare/zlib) on the > LD_LIBRARY_PATH (for jdk versions configured with > "--with-zlib=system", which is the default since jdk11): > > $ LD_LIBRARY_PATH=/ziptests/build/zlib-cloudflare > ./images/jdk/bin/java DeflateIn_InflateOut > java.lang.Exception: Stack trace > at java.base/java.lang.Thread.dumpStack(Thread.java:1379) > at DeflateIn_InflateOut.fail(DeflateIn_InflateOut.java:235) > at DeflateIn_InflateOut.check(DeflateIn_InflateOut.java:238) > at DeflateIn_InflateOut.SkipBytes(DeflateIn_InflateOut.java:204) > at DeflateIn_InflateOut.realMain(DeflateIn_InflateOut.java:229) > at DeflateIn_InflateOut.main(DeflateIn_InflateOut.java:243) > > Passed = 16 failed = 1 > Exception in thread "main" java.lang.AssertionError: Some tests failed > at DeflateIn_InflateOut.main(DeflateIn_InflateOut.java:245) > > The test may (and actually does) randomly fail at any of the subtests > executed in SkipBytes() which reuse "numReadable", the size of the > first deflated stream generated in that method. > > The fix is trivial. It is unnecessary to refill the source array with > random bytes before each subtest. Filling the array one time at test > startup time should be sufficient. > > Thank you and best regards, > Volker >
