Bug: https://bugs.openjdk.java.net/browse/JDK-8200118
Webrev: http://cr.openjdk.java.net/~shade/8200118/webrev.01/ This adds the relevant test to StringConcat family of tests, which asserts all strategies do the right thing. There was a bug in MH_* strategies caused by the already fixed bug in filterArguments [1], which this test was supposed to find, if existed before. Testing: run-test with jdk/jdk, run-test before/after filterArguments fix in jdk-updates/jdk10u Thanks, -Aleksey [1] https://bugs.openjdk.java.net/browse/JDK-8194554
