jruby · headius · Nov 5, 2025 · Nov 5, 2025
diff --git a/core/src/main/java/org/jruby/RubyHash.java b/core/src/main/java/org/jruby/RubyHash.java
@@ -2618,8 +2618,10 @@ public static RubyHash unmarshalFrom(org.jruby.runtime.marshal.UnmarshalStream i
         return result;
     }
 
-    public static RubyHash unmarshalFrom(ThreadContext context, RubyInputStream in, MarshalLoader input, boolean defaultValue) {
-        RubyHash result = (RubyHash) input.entry(Create.newHash(context));
+    public static RubyHash unmarshalFrom(ThreadContext context, RubyInputStream in, MarshalLoader input, boolean defaultValue, boolean identity) {
+        RubyHash result = Create.newHash(context);
+        if (identity) result.setComparedByIdentity(true);
+        result = (RubyHash) input.entry(result);
         int size = input.unmarshalInt(context, in);
 
         for (int i = 0; i < size; i++) {

diff --git a/core/src/main/java/org/jruby/runtime/marshal/MarshalDumper.java b/core/src/main/java/org/jruby/runtime/marshal/MarshalDumper.java
@@ -66,6 +66,7 @@
 import org.jruby.util.io.RubyOutputStream;
 
 import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.function.BiConsumer;
 
@@ -84,6 +85,7 @@
  * Marshals objects into Ruby's binary marshal format.
  */
 public class MarshalDumper {
+    private static final ByteList HASH_BYTELIST = new ByteList("Hash".getBytes(StandardCharsets.US_ASCII), false);
     private final int depthLimit;
     private int depth = 0;
     private final HashMapInt<IRubyObject> linkCache = new HashMapInt<>(true);
@@ -315,6 +317,10 @@ private void writeObjectData(ThreadContext context, RubyOutputStream out, IRubyO
                 case HASH: {
                     RubyHash hash = (RubyHash) value;
 
+                    if (hash.isComparedByIdentity()) {
+                        out.write(TYPE_UCLASS);
+                        dumpSymbol(out, HASH_BYTELIST);
+                    }
                     if (hash.getIfNone() == RubyBasicObject.UNDEF) {
                         out.write('{');
                     } else if (hash.hasDefaultProc()) {

diff --git a/core/src/main/java/org/jruby/runtime/marshal/MarshalLoader.java b/core/src/main/java/org/jruby/runtime/marshal/MarshalLoader.java
@@ -250,8 +250,8 @@ private IRubyObject objectFor(ThreadContext context, RubyInputStream in, int typ
             case TYPE_STRING -> objectForString(context, in, partial);
             case TYPE_REGEXP -> objectForRegexp(context, in, state, partial);
             case TYPE_ARRAY -> objectForArray(context, in, partial);
-            case TYPE_HASH -> objectForHash(context, in, partial);
-            case TYPE_HASH_DEF -> objectForHashDefault(context, in, partial);
+            case TYPE_HASH -> objectForHash(context, in, partial, false);
+            case TYPE_HASH_DEF -> objectForHashDefault(context, in, partial, false);
             case TYPE_STRUCT -> objectForStruct(context, in, partial);
             case TYPE_USERDEF -> objectForUserDef(context, in, state, partial);
             case TYPE_USRMARSHAL -> objectForUsrMarshal(context, in, extendedModules);
@@ -337,12 +337,12 @@ private IRubyObject objectForStruct(ThreadContext context, RubyInputStream in, b
         return leave(context, RubyStruct.unmarshalFrom(context, in, this), partial);
     }
 
-    private IRubyObject objectForHashDefault(ThreadContext context, RubyInputStream in, boolean partial) {
-        return leave(context, RubyHash.unmarshalFrom(context, in, this, true), partial);
+    private IRubyObject objectForHashDefault(ThreadContext context, RubyInputStream in, boolean partial, boolean identity) {
+        return leave(context, RubyHash.unmarshalFrom(context, in, this, true, identity), partial);
     }
 
-    private IRubyObject objectForHash(ThreadContext context, RubyInputStream in, boolean partial) {
-        return leave(context, RubyHash.unmarshalFrom(context, in, this, false), partial);
+    private IRubyObject objectForHash(ThreadContext context, RubyInputStream in, boolean partial, boolean identity) {
+        return leave(context, RubyHash.unmarshalFrom(context, in, this, false, identity), partial);
     }
 
     private IRubyObject objectForArray(ThreadContext context, RubyInputStream in, boolean partial) {
@@ -388,8 +388,9 @@ private IRubyObject objectForUClass(ThreadContext context, RubyInputStream in, b
 
         int type = r_byte(context, in);
         if (c == hashClass(context) && (type == TYPE_HASH || type == TYPE_HASH_DEF)) {
-            // FIXME: Missing logic to make the following methods use compare_by_identity (and construction of that)
-            return type == TYPE_HASH ? objectForHash(context, in, partial) : objectForHashDefault(context, in, partial);
+            return type == TYPE_HASH ?
+                    objectForHash(context, in, partial, true) :
+                    objectForHashDefault(context, in, partial, true);
         }
 
         IRubyObject obj = objectFor(context, in, type, null, partial, extendedModules);

diff --git a/spec/tags/ruby/core/marshal/dump_tags.txt b/spec/tags/ruby/core/marshal/dump_tags.txt
@@ -12,8 +12,6 @@ fails:Marshal.dump with an object responding to #_dump dumps the String in multi
 fails:Marshal.dump with an object responding to #_dump raises TypeError if an Object is an instance of an anonymous class
 fails:Marshal.dump with a Class dumps a class with multibyte characters in name
 fails:Marshal.dump with a Module dumps a module with multibyte characters in name
-fails:Marshal.dump with a Hash dumps a Hash with compare_by_identity
-fails:Marshal.dump with a Hash dumps a Hash subclass with compare_by_identity
 fails:Marshal.dump with an Object raises TypeError if an Object extends an anonymous module
 fails:Marshal.dump with a Time dumps a Time subclass with multibyte characters in name
 fails:Marshal.dump with a Time raises TypeError with an anonymous Time subclass

diff --git a/spec/tags/ruby/core/marshal/load_tags.txt b/spec/tags/ruby/core/marshal/load_tags.txt
@@ -8,8 +8,6 @@ fails:Marshal.load when called with freeze: true returns frozen object having #_
 fails:Marshal.load when called with freeze: true returns frozen object responding to #marshal_dump and #marshal_load
 fails:Marshal.load when called with freeze: true returns frozen object extended by a module
 fails:Marshal.load when called on objects with custom _dump methods loads the String in multibyte encoding
-fails:Marshal.load for a Hash preserves compare_by_identity behaviour
-fails:Marshal.load for a Hash preserves compare_by_identity behaviour for a Hash subclass
 fails:Marshal.load for a Rational loads
 fails:Marshal.load for a Complex loads
 fails:Marshal.load raises an ArgumentError when the dumped data is truncated

diff --git a/spec/tags/ruby/core/marshal/restore_tags.txt b/spec/tags/ruby/core/marshal/restore_tags.txt
@@ -8,8 +8,6 @@ fails:Marshal.restore when called with freeze: true returns frozen object having
 fails:Marshal.restore when called with freeze: true returns frozen object responding to #marshal_dump and #marshal_load
 fails:Marshal.restore when called with freeze: true returns frozen object extended by a module
 fails:Marshal.restore when called on objects with custom _dump methods loads the String in multibyte encoding
-fails:Marshal.restore for a Hash preserves compare_by_identity behaviour
-fails:Marshal.restore for a Hash preserves compare_by_identity behaviour for a Hash subclass
 fails:Marshal.restore for a Rational loads
 fails:Marshal.restore for a Complex loads
 fails:Marshal.restore raises an ArgumentError when the dumped data is truncated

diff --git a/test/mri/excludes/TestMarshal.rb b/test/mri/excludes/TestMarshal.rb
@@ -1,7 +1,5 @@
 exclude :test_change_struct, "work in progress"
 exclude :test_class_ivar, "needs investigation"
-exclude :test_hash_compared_by_identity, "work in progress"
-exclude :test_hash_default_compared_by_identity, "work in progress"
 exclude :test_inconsistent_struct, "needs investigation"
 exclude :test_load_range_as_struct, "needs investigation"
 exclude :test_marshal_complex, "needs investigation"