disable backtrace generation for wait non-block errors (use an empty array)

... little more confusing than a `nil` but for now has todo (until jruby/jruby#3488)

Author: kares

src/main/java/org/jruby/ext/openssl/SSL.java

@@ -38,6 +38,7 @@
 import org.jruby.runtime.Block;
 import org.jruby.runtime.ThreadContext;
 import org.jruby.runtime.builtin.IRubyObject;
+import org.jruby.util.SafePropertyAccessor;
 
 /**
  * @author <a href="mailto:[email protected]">Ola Bini</a>
@@ -177,13 +178,20 @@ public static RaiseException newSSLErrorWaitWritable(Ruby runtime, String messag
         return newCustomSSLError(runtime, "SSLErrorWaitWritable", message);
     }
 
+    // -Djruby.openssl.ssl.error_wait_nonblock.backtrace=false disables backtrace for WaitReadable/Writable
+    private static final boolean waitErrorBacktrace =
+        SafePropertyAccessor.getBoolean("jruby.openssl.ssl.error_wait_nonblock.backtrace", false);
+
     private static RaiseException newCustomSSLError(final Ruby runtime, final String name,
         final String message) {
         RubyClass errorClass = _SSL(runtime).getClass(name);
         if ( errorClass == null ) { // < Ruby 2.0
             errorClass = _SSL(runtime).getClass("SSLError"); // fallback
         }
-        return Utils.newError(runtime, errorClass, message, false);
+        if ( waitErrorBacktrace ) {
+            return Utils.newError(runtime, errorClass, message, false);
+        }
+        return Utils.newErrorWithoutTrace(runtime, errorClass, message, false);
     }
 
     static RubyModule _SSL(final Ruby runtime) {

src/main/java/org/jruby/ext/openssl/Utils.java

@@ -70,6 +70,11 @@ static RaiseException newRuntimeError(Ruby runtime, String msg) {
         return new RaiseException(runtime, runtime.getRuntimeError(), msg, true);
     }
 
+    static RaiseException newErrorWithoutTrace(Ruby runtime, RubyClass errorClass, String message, boolean nativeException) {
+        final IRubyObject backtrace = runtime.newEmptyArray(); // runtime.getNil();
+        return new RaiseException(runtime, errorClass, message, backtrace, nativeException);
+    }
+
     static RaiseException newError(Ruby runtime, RubyClass errorClass, String message, boolean nativeException) {
         return new RaiseException(runtime, errorClass, message, nativeException);
     }