[Truffle] Fixed a bad guard.

jruby · Mar 14, 2016 · c289445 · c289445
1 parent 9d3d6dd
commit c289445
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/truffle/src/main/java/org/jruby/truffle/core/rope/RopeNodes.java b/truffle/src/main/java/org/jruby/truffle/core/rope/RopeNodes.java
@@ -287,7 +287,7 @@ public Rope concatSubstringLeaf(SubstringRope left, LeafRope right, Encoding enc
             return concat(left, right, encoding, sameCodeRangeProfile, brokenCodeRangeProfile, isLeftSingleByteOptimizableProfile);
         }
 
-        @Specialization(guards = { "!isMutableRope(left)" })
+        @Specialization(guards = { "!left.isEmpty()", "!right.isEmpty()", "!isMutableRope(left)" })
         public Rope concat(Rope left, Rope right, Encoding encoding,
                            @Cached("createBinaryProfile()") ConditionProfile sameCodeRangeProfile,
                            @Cached("createBinaryProfile()") ConditionProfile brokenCodeRangeProfile,