Discovered it with ARM32 tier1 tests, which runs with -CompactStrings by
default. But the bug is actually generic:
$ CONF=linux-x86_64-server-fastdebug make run-test
TEST=java/lang/StringBuilder/Insert.java TEST_VM_OPTS="-XX:-CompactStrings"
test Insert.insertOffset(): failure
java.lang.AssertionError: expected [??abc] but found [efabc]
at org.testng.Assert.fail(Assert.java:94)
at org.testng.Assert.failNotEquals(Assert.java:496)
at org.testng.Assert.assertEquals(Assert.java:125)
at org.testng.Assert.assertEquals(Assert.java:178)
at org.testng.Assert.assertEquals(Assert.java:188)
at Insert.insertOffset(Insert.java:45)
at
java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
I believe this is a regression from
[JDK-8254082](https://bugs.openjdk.java.net/browse/JDK-8254082).
Additional testing:
- [x] Linux x86_64 `tier1` default, passes
- [x] Linux x86_64 `tier1`, `-XX:-CompactStrings`, passes modulo two testbugs
([JDK-8260933](https://bugs.openjdk.java.net/browse/JDK-8260933),
[JDK-8260934](https://bugs.openjdk.java.net/browse/JDK-8260934))
- [x] Linux ARM32, affected test now passes
-------------
Commit messages:
- 8260927: StringBuilder::insert is incorrect without Compact Strings
Changes: https://git.openjdk.java.net/jdk16/pull/143/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=143&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8260927
Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
Patch: https://git.openjdk.java.net/jdk16/pull/143.diff
Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/143/head:pull/143
PR: https://git.openjdk.java.net/jdk16/pull/143
