jruby · Jun 22, 2015 · Jun 22, 2015
diff --git a/spec/truffle/tags/core/env/shift_tags.txt b/spec/truffle/tags/core/env/shift_tags.txt
diff --git a/spec/truffle/tags/core/env/size_tags.txt b/spec/truffle/tags/core/env/size_tags.txt
diff --git a/spec/truffle/tags/core/env/store_tags.txt b/spec/truffle/tags/core/env/store_tags.txt
@@ -1,8 +1,2 @@
-fails:ENV.store deletes the environment variable when the value is nil
-fails:ENV.store coerces the key argument with #to_str
-fails:ENV.store coerces the value argument with #to_str
-fails:ENV.store raises TypeError when the key is not coercible to String
-fails:ENV.store raises TypeError when the value is not coercible to String
 fails:ENV.store raises Errno::EINVAL when the key contains the '=' character
 fails:ENV.store raises Errno::EINVAL when the key is an empty string
-fails:ENV.store does nothing when the key is not a valid environment variable key and the value is nil
diff --git a/spec/truffle/tags/core/env/to_a_tags.txt b/spec/truffle/tags/core/env/to_a_tags.txt
diff --git a/spec/truffle/tags/core/env/to_h_tags.txt b/spec/truffle/tags/core/env/to_h_tags.txt
diff --git a/spec/truffle/tags/core/env/to_hash_tags.txt b/spec/truffle/tags/core/env/to_hash_tags.txt
diff --git a/spec/truffle/tags/core/env/to_s_tags.txt b/spec/truffle/tags/core/env/to_s_tags.txt
diff --git a/spec/truffle/tags/core/env/values_at_tags.txt b/spec/truffle/tags/core/env/values_at_tags.txt
diff --git a/spec/truffle/tags/core/env/values_tags.txt b/spec/truffle/tags/core/env/values_tags.txt
diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/core/PointerGuards.java b/truffle/src/main/java/org/jruby/truffle/nodes/core/PointerGuards.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+
+package org.jruby.truffle.nodes.core;
+
+
+import org.jruby.truffle.nodes.rubinius.PointerNodes;
+import org.jruby.truffle.runtime.core.RubyBasicObject;
+
+public class PointerGuards {
+
+    public static boolean isNullPointer(RubyBasicObject pointer) {
+        return PointerNodes.getPointer(pointer) == PointerNodes.NULL_POINTER;
+    }
+
+}
+
diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/rubinius/PointerPrimitiveNodes.java b/truffle/src/main/java/org/jruby/truffle/nodes/rubinius/PointerPrimitiveNodes.java
@@ -16,6 +16,7 @@
 import com.oracle.truffle.api.object.*;
 import com.oracle.truffle.api.source.SourceSection;
 import jnr.ffi.Pointer;
+import org.jruby.truffle.nodes.core.PointerGuards;
 import org.jruby.truffle.nodes.core.StringNodes;
 import org.jruby.truffle.nodes.objects.Allocator;
 import org.jruby.truffle.runtime.RubyContext;
@@ -298,13 +299,19 @@ public RubyBasicObject address(RubyBasicObject pointer, RubyString string, int m
     }
 
     @RubiniusPrimitive(name = "pointer_read_string_to_null")
+    @ImportStatic(PointerGuards.class)
     public static abstract class PointerReadStringToNullPrimitiveNode extends RubiniusPrimitiveNode {
 
         public PointerReadStringToNullPrimitiveNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
         }
 
-        @Specialization
+        @Specialization(guards = "isNullPointer(pointer)")
+        public RubyBasicObject readNullPointer(RubyBasicObject pointer) {
+            return StringNodes.createEmptyString(getContext().getCoreLibrary().getStringClass());
+        }
+
+        @Specialization(guards = "!isNullPointer(pointer)")
         public RubyBasicObject readStringToNull(RubyBasicObject pointer) {
             return createString(MemoryIO.getInstance().getZeroTerminatedByteArray(PointerNodes.getPointer(pointer).address()));
         }