Hi,
Please review this change to how the platform encoding is determined on
Mac when loading agents.
Webrev: http://cr.openjdk.java.net/~bchristi/8072130/webrev.01.cleanned/
Additional details in the bug report:
https://bugs.openjdk.java.net/browse/JDK-8072130
Some background:
Since JDK 8, if MacOS reports an encoding of US-ASCII, but no encoding
hints are provided in environment variables (LANG, LC_ALL, LC_CTYPE),
the JDK uses UTF-8 instead; see JDK-8011194[1]. (This allowed apps
launched via double-clicked jar to display files correctly for non-ASCII
languages).
A similar encoding tweak was not made in the code path used for loading
agents.
This can come into play when an agent jar includes a Boot-Class-Path
entry containing non-ASCII characters. iconv() gets setup to convert
UTF-8 to US-ASCII[2], but will fail when encountering extended
characters in the entry, so the path in question is not added to the
bootclasspath[3]. This will likely lead to a ClassNotFoundException.
When java/lang/instrument/BootClassPath/BootClassPathTest.sh is run on a
Mac with no values for LANG/LC_ALL/LC_CTYPE, Setup.java sees a default
encoding of UTF-8 (per 8011194) and creates Agent.jar with a
Boot-Class-Path that includes non-ASCII characters. But the
Boot-Class-Path entry gets skipped when loading Agent.jar, so the
AgentSupport class can't be found.
I propose this be fixed by adding the same UTF-8 encoding adjustment on
MacOS from 8011194 to the agent loading code path.
An additional note:
This bug was challenging to reproduce, in large part because the 8011194
code checks for an absent env var (getenv() == null), but not for env
vars with a blank/empty string value (getenv() == ""), so the test
environment had to be setup in a specific way (e.g. 'unset LANG' vs
'export LANG=') to reproduce this bug. So I'd like to update the code
to also check for empty string. I also added a couple small
improvements to the test.
Thanks!
-Brent
1. https://bugs.openjdk.java.net/browse/JDK-8011194
2.
http://hg.openjdk.java.net/jdk/jdk/file/0517bd2a0eda/src/java.instrument/unix/native/libinstrument/EncodingSupport_md.c#l87
3.
http://hg.openjdk.java.net/jdk/jdk/file/0517bd2a0eda/src/java.instrument/share/native/libinstrument/InvocationAdapter.c#l873
