Auto-populate Exception#cause only on first raise. Fixes #3654.

jruby · Feb 14, 2016 · 2bfeb1f · 2bfeb1f
1 parent ceb153d
commit 2bfeb1f
Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/core/src/main/java/org/jruby/RubyException.java b/core/src/main/java/org/jruby/RubyException.java
@@ -70,7 +70,7 @@ public RubyException(Ruby runtime, RubyClass rubyClass, String message) {
         super(runtime, rubyClass);
 
         this.message = message == null ? runtime.getNil() : runtime.newString(message);
-        this.cause = runtime.getNil();
+        this.cause = RubyBasicObject.UNDEF;
     }
 
     @JRubyMethod(optional = 2, visibility = PRIVATE)
@@ -196,13 +196,20 @@ public static IRubyObject op_eqq(ThreadContext context, IRubyObject recv, IRubyO
     @JRubyMethod(name = "cause")
     public IRubyObject cause(ThreadContext context) {
         assert cause != null;
+
+        if (cause == RubyBasicObject.UNDEF) return context.nil;
+
         return cause;
     }
 
     public void setCause(IRubyObject cause) {
         this.cause = cause;
     }
 
+    public IRubyObject getCause() {
+        return cause;
+    }
+
     public void setBacktraceData(BacktraceData backtraceData) {
         this.backtraceData = backtraceData;
     }

diff --git a/core/src/main/java/org/jruby/RubyKernel.java b/core/src/main/java/org/jruby/RubyKernel.java
@@ -79,6 +79,7 @@
 import java.util.HashSet;
 import java.util.Map;
 
+import static org.jruby.RubyBasicObject.UNDEF;
 import static org.jruby.RubyEnumerator.enumeratorizeWithSize;
 import static org.jruby.anno.FrameField.BLOCK;
 import static org.jruby.anno.FrameField.FILENAME;
@@ -842,7 +843,9 @@ public static IRubyObject raise(ThreadContext context, IRubyObject recv, IRubyOb
             printExceptionSummary(context, runtime, raise.getException());
         }
 
-        if ( argc > 0 && cause != raise.getException() ) raise.getException().setCause(cause);
+        if (argc > 0 && raise.getException().getCause() == UNDEF) {
+            raise.getException().setCause(cause);
+        }
 
         throw raise;
     }