RFR 12 : 8072130 : java/lang/instrument/BootClassPath/BootClassPathTest.sh fails on Mac OSX

[Xueming Shen]

+1

On 9/18/18, 9:42 AM, Brent Christian wrote:
> Any thoughts on this change?  -B
>
> On 9/11/18 3:41 PM, Brent Christian wrote:
>> 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 
>>
>>