JNIEnv::GetStringUTFChars() crashes when Java code is obfuscated

[thedude]

I'm getting ready to release my app, and trying out an obfuscated
release build.

When I obfuscate, my native code crashes on calls to
JNIEnv::GetStringUTFChars(). It works perfetly when not obfuscated.
Is there a line I need to add to proguard.cfg to have it avoid
obfuscating stuff used by JNIEnv?

Thanks.

[thedude]

UPDATE: 

I have verified that the problem is caused by something being 
obfuscated that shouldn't be. 

When I add the following lines to my proguard.cfg (which obviously 
defeats the purpose of obfuscating, since it prevents anything from being obfuscated) the crash goes away: 

-keep class ** { 
 <methods>; 
 <fields>; 
} 

But I haven't been able to come up with a narrower exclusion that 
prevents JNIEnv::GetStringUTFChars() from crashing. 

If I had the source code to JNIEnv::GetStringUTFChars(), maybe I could 
dig in and figure out which fields or methods it's trying to access. 
I haven't been able to find the source though. 

Help? 

[Emile Belanger]

Sorry I know this is very old, can you remember if you fixed this, and how?

Thanks!