use identity hash code when Hash compare_by_identity set (fixes #3650)

jruby · Feb 18, 2016 · 0285d99 · 0285d99
1 parent 9b2bbcd
commit 0285d99
Showing 2 changed files with 27 additions and 5 deletions.
diff --git a/core/src/main/java/org/jruby/RubyHash.java b/core/src/main/java/org/jruby/RubyHash.java
@@ -485,6 +485,11 @@ protected static int hashValue(final int h) {
         return MRI_HASH ? MRIHashValue(h) : JavaSoftHashValue(h);
     }
 
+    protected final int hashValue(final IRubyObject key) {
+        final int h = isComparedByIdentity() ? System.identityHashCode(key) : key.hashCode();
+        return MRI_HASH ? MRIHashValue(h) : JavaSoftHashValue(h);
+    }
+
     private static int bucketIndex(final int h, final int length) {
         return MRI_HASH ? MRIBucketIndex(h, length) : JavaSoftBucketIndex(h, length);
     }
@@ -518,7 +523,7 @@ protected void internalPut(final IRubyObject key, final IRubyObject value, final
     }
 
     protected void internalPutSmall(final IRubyObject key, final IRubyObject value, final boolean checkForExisting) {
-        final int hash = hashValue(key.hashCode());
+        final int hash = hashValue(key);
         final int i = bucketIndex(hash, table.length);
 
         // if (table[i] != null) collisions++;
@@ -547,7 +552,7 @@ protected IRubyObject internalGet(IRubyObject key) { // specialized for value
     protected RubyHashEntry internalGetEntry(IRubyObject key) {
         if (size == 0) return NO_ENTRY;
 
-        final int hash = hashValue(key.hashCode());
+        final int hash = hashValue(key);
         for (RubyHashEntry entry = table[bucketIndex(hash, table.length)]; entry != null; entry = entry.next) {
             if (internalKeyExist(entry, hash, key)) {
                 return entry;
@@ -567,12 +572,12 @@ private boolean internalKeyExist(RubyHashEntry entry, int hash, IRubyObject key)
     protected RubyHashEntry internalDelete(final IRubyObject key) {
         if (size == 0) return NO_ENTRY;
 
-        return internalDelete(hashValue(key.hashCode()), MATCH_KEY, key);
+        return internalDelete(hashValue(key), MATCH_KEY, key);
     }
 
     protected RubyHashEntry internalDeleteEntry(final RubyHashEntry entry) {
         // n.b. we need to recompute the hash in case the key object was modified
-        return internalDelete(hashValue(entry.key.hashCode()), MATCH_ENTRY, entry);
+        return internalDelete(hashValue(entry.key), MATCH_ENTRY, entry);
     }
 
     private final RubyHashEntry internalDelete(final int hash, final EntryMatchType matchType, final Object obj) {
@@ -923,7 +928,7 @@ public RubyHash rehash() {
             oldTable[j] = null;
             while (entry != null) {
                 RubyHashEntry next = entry.next;
-                entry.hash = hashValue(entry.key.hashCode()); // update the hash value
+                entry.hash = hashValue(entry.key); // update the hash value
                 int i = bucketIndex(entry.hash, newTable.length);
                 entry.next = newTable[i];
                 newTable[i] = entry;

diff --git a/test/jruby/test_hash.rb b/test/jruby/test_hash.rb
@@ -1,6 +1,7 @@
 require 'test/unit'
 
 class TestHash < Test::Unit::TestCase
+
   def test_clone_copies_default_initializer
     hash = Hash.new { |h, k| h[k] = 0 }
     clone = hash.clone
@@ -88,7 +89,23 @@ def test_yield_arguments
     passed = []; ret = hash.collect { |k,v| passed << k; passed << v; passed.size < 3 }
     assert_equal [:a, 1, :b, 2, :c, 3], passed
     assert_equal [true, false, false], ret
+  end
 
+  def test_compare_by_identity
+    hash = {}.compare_by_identity
+    arr = [0]
+    hash[arr] = 42
+    arr[0] = 1
+    assert_equal 42, hash[arr]
+
+    hash = {}.compare_by_identity
+    arr1 = []; arr2 = []
+    hash[arr2] = 2
+    assert_equal nil, hash[arr1]
+    assert_equal 2, hash[arr2]
+    hash[arr1] = 1
+    assert_equal 1, hash[arr1]
+    assert_equal 2, hash[arr2]
   end
 
 end