jruby · headius · Mar 1, 2026 · Nov 11, 2025 · Nov 11, 2025 · Nov 11, 2025
diff --git a/.gitignore b/.gitignore
@@ -58,7 +58,6 @@ lib/ruby/stdlib/*.jar
 lib/ruby/stdlib/ant*
 lib/ruby/stdlib/benchmark*
 lib/ruby/stdlib/bundler*
-lib/ruby/stdlib/cgi*
 lib/ruby/stdlib/debug*
 lib/ruby/stdlib/delegate*
 lib/ruby/stdlib/did_you_mean*
@@ -125,6 +124,7 @@ lib/ruby/stdlib/un*
 lib/ruby/stdlib/uri*
 lib/ruby/stdlib/yaml*
 lib/ruby/stdlib/weakref*
+lib/ruby/stdlib/win32/registry.rb
 
 release.properties
 share

diff --git a/core/pom.rb b/core/pom.rb
@@ -53,8 +53,8 @@
   jar 'com.github.jnr:jffi:${jffi.version}'
   jar 'com.github.jnr:jffi:${jffi.version}:native'
 
-  jar 'org.jruby.joni:joni:2.2.6'
-  jar 'org.jruby.jcodings:jcodings:1.0.63'
+  jar 'org.jruby.joni:joni:2.2.7'
+  jar 'org.jruby.jcodings:jcodings:1.0.64'
   jar 'org.jruby:dirgra:0.5'
 
   jar 'com.headius:invokebinder:1.14'

diff --git a/core/pom.xml b/core/pom.xml
@@ -55,9 +55,9 @@ DO NOT MODIFY - GENERATED CODE
     <test.results.dir>${build.dir}/test-results</test.results.dir>
     <tzdata.scope>provided</tzdata.scope>
     <tzdata.version>2019c</tzdata.version>
-    <version.ruby>3.4.5</version.ruby>
-    <version.ruby.major>3.4</version.ruby.major>
-    <version.ruby.minor>5</version.ruby.minor>
+    <version.ruby>4.0.0</version.ruby>
+    <version.ruby.major>4.0</version.ruby.major>
+    <version.ruby.minor>0</version.ruby.minor>
   </properties>
   <dependencies>
     <dependency>
@@ -149,12 +149,12 @@ DO NOT MODIFY - GENERATED CODE
     <dependency>
       <groupId>org.jruby.joni</groupId>
       <artifactId>joni</artifactId>
-      <version>2.2.6</version>
+      <version>2.2.7</version>
     </dependency>
     <dependency>
       <groupId>org.jruby.jcodings</groupId>
       <artifactId>jcodings</artifactId>
-      <version>1.0.63</version>
+      <version>1.0.64</version>
     </dependency>
     <dependency>
       <groupId>org.jruby</groupId>

diff --git a/core/src/main/java/org/jruby/Ruby.java b/core/src/main/java/org/jruby/Ruby.java
@@ -50,6 +50,7 @@
 import org.jruby.exceptions.LocalJumpError;
 import org.jruby.exceptions.SystemExit;
 import org.jruby.ext.jruby.JRubyUtilLibrary;
+import org.jruby.ext.set.RubySet;
 import org.jruby.ext.thread.ConditionVariable;
 import org.jruby.ext.thread.Mutex;
 import org.jruby.ext.thread.Queue;
@@ -518,6 +519,8 @@ private Ruby(RubyInstanceConfig config) {
 
         dataClass = RubyData.createDataClass(context, objectClass);
 
+        setClass = RubySet.createSetClass(context, objectClass, enumerableModule);
+
         // everything booted, so SizedQueue should be available; set up root fiber
         ThreadFiber.initRootFiber(context, context.getThread());
 
@@ -602,6 +605,8 @@ private void initBootLibraries(ThreadContext context) {
         loadService.provide("thread.rb");
         loadService.provide("fiber.rb");
         loadService.provide("ruby2_keywords.rb");
+        loadService.provide("set.rb");
+        loadService.provide("pathname.rb");
 
         // Load preludes
         initRubyPreludes();
@@ -2508,6 +2513,10 @@ public RubyClass getData() {
         return dataClass;
     }
 
+    public RubyClass getSet() {
+        return setClass;
+    }
+
     /** The default Ruby Random object for this runtime */
     private RubyRandom defaultRandom;
 
@@ -4391,7 +4400,7 @@ public RaiseException newFloatDomainError(String message){
     }
 
     public RaiseException newMathDomainError(String message) {
-        return newRaiseException(getMathDomainError(), "Numerical argument is out of domain - \"" + message + "\"");
+        return newRaiseException(getMathDomainError(), "Numerical argument is out of domain - " + message);
     }
 
     public RaiseException newEncodingError(String message){
@@ -4452,12 +4461,13 @@ public RaiseException newBufferMaskError(String message) {
      * @return a new RaiseException wrapping a new Ruby exception
      */
     public RaiseException newRaiseException(RubyClass exceptionClass, String message) {
-        IRubyObject cause = getCurrentContext().getErrorInfo();
+        ThreadContext context = getCurrentContext();
+        IRubyObject cause = context.getErrorInfo();
 
         RaiseException exception = RaiseException.from(this, exceptionClass, message);
 
         if (cause != null && !cause.isNil()) {
-            exception.getException().setCause(cause);
+            exception.getException().setCause(context, cause);
         }
 
         return exception;
@@ -5076,7 +5086,6 @@ public void setChdirThread(RubyThread thread) {
     public RubyThread getChdirThread() { return this.chdirCurrentThread; }
 
     public RubyStackTraceElement getChdirLocation() { return this.chdirLocation; }
-
     /**
      * Because RubyString.equals does not consider encoding, and MRI's logic for deduplication does need to consider
      * encoding, we use a wrapper object as the key. These wrappers need to be used on all get operations, so if we
@@ -5316,6 +5325,7 @@ public interface RecursiveFunctionEx<T> extends ThreadContext.RecursiveFunctionE
     private final RubyClass closedQueueError;
     private final RubyClass sizedQueueClass;
     private final RubyClass dataClass;
+    private final RubyClass setClass;
 
     private RubyClass tmsStruct;
     private RubyClass passwdStruct;

diff --git a/core/src/main/java/org/jruby/RubyArray.java b/core/src/main/java/org/jruby/RubyArray.java
@@ -58,6 +58,7 @@
 import org.jruby.runtime.JavaSites;
 import org.jruby.runtime.ThreadContext;
 import org.jruby.runtime.builtin.IRubyObject;
+import org.jruby.runtime.callsite.CachingCallSite;
 import org.jruby.runtime.marshal.MarshalDumper;
 import org.jruby.runtime.marshal.MarshalLoader;
 import org.jruby.specialized.RubyArrayOneObject;
@@ -1357,6 +1358,12 @@ public void copyInto(IRubyObject[] target, int start, int len) {
     @Override
     public abstract boolean equals(Object other);
 
+    @JRubyMethod
+    public abstract IRubyObject rfind(ThreadContext context, Block block);
+
+    @JRubyMethod
+    public abstract IRubyObject rfind(ThreadContext context, IRubyObject ifnone, Block block);
+
     @Deprecated(since = "10.0.0.0", forRemoval = true)
     @SuppressWarnings("removal")
     public static void marshalTo(RubyArray array, org.jruby.runtime.marshal.MarshalStream output) throws IOException {

diff --git a/core/src/main/java/org/jruby/RubyArrayNative.java b/core/src/main/java/org/jruby/RubyArrayNative.java
@@ -39,6 +39,7 @@
 package org.jruby;
 
 import org.jcodings.specific.USASCIIEncoding;
+import org.jruby.anno.JRubyMethod;
 import org.jruby.api.Create;
 import org.jruby.api.JRubyAPI;
 import org.jruby.ast.util.ArgsUtil;
@@ -922,21 +923,10 @@ public T eltInternalSet(int offset, T item) {
 
     public IRubyObject fetch_values(ThreadContext context, IRubyObject[] args, Block block) {
         int length = args.length;
-        if (length == 0) return Create.newEmptyArray(context);
-
-        int arraySize = size();
-        var result = Create.allocArray(context, length);
-        for (int i = 0; i < length; i++) {
-            int index = toInt(context, args[i]);
-            // FIXME: lookup the bounds part of this in error message??
-            if (index >= arraySize) {
-                if (!block.isGiven()) throw indexError(context, "index " + index + " outside of array bounds: 0...0");
-                result.append(context, block.yield(context, asFixnum(context, index)));
-            } else {
-                result.append(context, eltOk(index));
-            }
+        RubyArray result = RubyArrayNative.newBlankArrayInternal(context.runtime, length);
+        for (int i = 0; i < args.length; i++) {
+            result.storeInternal(context, i, fetch(context, args[i], block));
         }
-
         return result;
     }
 
@@ -5205,6 +5195,25 @@ public boolean equals(Object other) {
         return false;
     }
 
+    @JRubyMethod
+    public IRubyObject rfind(ThreadContext context, Block block) {
+        return rfind(context, context.nil, block);
+    }
+
+    @JRubyMethod
+    public IRubyObject rfind(ThreadContext context, IRubyObject ifnone, Block block) {
+        CachingCallSite self_each = sites(context).self_each;
+        if (!self_each.isBuiltin(this)) return RubyEnumerable.detectCommon(context, self_each, this, block);
+
+        for (int i = realLength - 1; i >= 0; i--) {
+            IRubyObject value = eltOk(i);
+
+            if (block.yield(context, value).isTrue()) return value;
+        }
+
+        return ifnone != null && !ifnone.isNil() ? sites(context).call.call(context, ifnone, ifnone) : context.nil;
+    }
+
     private static IRubyObject safeArrayRef(ThreadContext context, IRubyObject[] values, int i) {
         try {
             return values[i];

diff --git a/core/src/main/java/org/jruby/RubyBasicObject.java b/core/src/main/java/org/jruby/RubyBasicObject.java
@@ -315,7 +315,7 @@ protected final void testFrozen(String message) {
    protected final void testFrozen() {
        if (isFrozen()) {
            var context = getRuntime().getCurrentContext();
-           throw context.runtime.newFrozenError((isClass() ? "Class: " : (isModule() ? "Module: " : "object: ")) + inspect(context), this);
+           throw context.runtime.newFrozenError((isClass() ? "Class: " : (isModule() ? "Module: " : "Object: ")) + inspect(context), this);
        }
    }
 
@@ -905,6 +905,7 @@ private static void initCopy(ThreadContext context, IRubyObject clone, IRubyObje
             RubyModule cloneMod = (RubyModule)clone;
             cloneMod.syncConstants((RubyModule)original);
             cloneMod.syncClassVariables((RubyModule)original);
+            cloneMod.initializeCopiedModule(context, original);
         }
     }
 
@@ -1028,16 +1029,20 @@ protected RubyClass getSingletonClassCloneAndAttach(ThreadContext context, RubyB
         MetaClass clone = new MetaClass(context.runtime, klass.getSuperClass(), attach);
         clone.flags = klass.flags;
 
-        clone.setMetaClass(this instanceof RubyClass ? clone : klass.getSingletonClassCloneAndAttach(context, null));
+        if (this instanceof RubyClass) {
+            clone.setMetaClass(clone);
+        } else {
+            MetaClass metaClone = (MetaClass) klass.getSingletonClassCloneAndAttach(context, null);
+            clone.setMetaClass(metaClone);
+            metaClone.setAttached(clone);
+        }
 
         if (klass.hasVariables()) clone.syncVariables(klass);
 
         clone.syncConstants(klass);
 
         klass.cloneMethods(context, clone);
 
-        ((MetaClass) clone.getMetaClass()).setAttached(clone);
-
         return clone;
     }
 
@@ -1132,24 +1137,26 @@ public IRubyObject inspect() {
     // MRI: rb_obj_inspect
     public IRubyObject inspect(ThreadContext context) {
         return !isImmediate() && !(this instanceof RubyModule) && hasVariables() ?
-                hashyInspect() : to_s(context);
+                hashyInspect(context) : to_s(context);
     }
 
+    @Deprecated(since = "10.1.0.0")
     public final IRubyObject hashyInspect() {
-        final Ruby runtime = getRuntime();
+        return hashyInspect(getRuntime().getCurrentContext());
+    }
 
-        RubyString part = inspectPrefix(runtime.getCurrentContext(), metaClass.getRealClass(), inspectHashCode());
+    public final IRubyObject hashyInspect(ThreadContext context) {
+        IRubyObject ivars = Helpers.invokeChecked(context, this, sites(context).instance_variables_to_inspect_checked);
 
-        if (runtime.isInspecting(this)) {
-            encStrBufCat(runtime, part, SPACE_DOT_DOT_DOT_GT);
-            return part;
-        }
-        try {
-            runtime.registerInspecting(this);
-            return inspectObj(runtime, part);
-        } finally {
-            runtime.unregisterInspecting(this);
+        if (ivars != null && !ivars.isNil() && !(ivars instanceof RubyArray)) {
+            throw typeError(context, "Expected #instance_variables_to_inspect to return an Array or nil, but it returned " + ivars.getMetaClass());
         }
+
+        RubyString part = inspectPrefix(context, metaClass.getRealClass(), inspectHashCode());
+
+        return context.execRecursive(
+                (ctx, p, obj, recur) -> inspectObj(ctx, p, ivars, recur),
+                part, this, "inspect");
     }
 
     // MRI: rb_inspect, which does dispatch
@@ -1187,31 +1194,63 @@ protected int inspectHashCode() {
      * The internal helper method that takes care of the part of the
      * inspection that inspects instance variables.
      */
-    private RubyString inspectObj(final Ruby runtime, RubyString part) {
-        final ThreadContext context = runtime.getCurrentContext();
+    private RubyString inspectObj(final ThreadContext context, RubyString part, IRubyObject ivars, boolean recur) {
+        Ruby runtime = context.runtime;
+
+        if (recur) {
+            encStrBufCat(runtime, part, SPACE_DOT_DOT_DOT_GT);
+            return part;
+        }
+
+        if (ivars == null || ivars.isNil()) {
+            // no ivars specified, do all of them
+            boolean first = true;
+            for (Map.Entry<String, VariableAccessor> entry : metaClass.getVariableTableManager().getVariableAccessorsForRead().entrySet()) {
+                VariableAccessor accessor = entry.getValue();
+                String name = entry.getKey();
 
-        boolean first = true;
-        for (Map.Entry<String, VariableAccessor> entry : metaClass.getVariableTableManager().getVariableAccessorsForRead().entrySet()) {
-            Object value = entry.getValue().get(this);
-            if (!(value instanceof IRubyObject)) continue;
-            RubySymbol symbol = asSymbol(context, entry.getKey());
-            if (!symbol.validInstanceVariableName()) continue;
+                if (appendInstanceVariable(context, part, accessor, name, first, runtime)) continue;
+
+                first = false;
+            }
+        } else {
+            // ivars specified, do only those
+            RubyArray ivarsAry = Convert.castAsArray(context, ivars);
 
-            IRubyObject obj = (IRubyObject) value;
+            boolean first = true;
+            Map<String, VariableAccessor> accessors = metaClass.getVariableTableManager().getVariableAccessorsForRead();
+            for (int i = 0; i < ivarsAry.size(); i++) {
+                String name = ivarsAry.eltOk(i).toString();
+                VariableAccessor accessor = accessors.get(name);
+                if (accessor == null) continue;
 
-            if (!first) encStrBufCat(runtime, part, COMMA);
-            encStrBufCat(runtime, part, SPACE);
-            // FIXME: bytelist_love: EPICLY wrong but something in MRI gets around identifiers of arbitrary encoding.
-            encStrBufCat(runtime, part, symbol.asString().encode(context, encodingService(context).convertEncodingToRubyEncoding(part.getEncoding())).asString().getByteList());
-            encStrBufCat(runtime, part, EQUALS);
-            encStrBufCat(runtime, part, sites(context).inspect.call(context, obj, obj).convertToString().getByteList());
+                if (appendInstanceVariable(context, part, accessor, name, first, runtime)) continue;
 
-            first = false;
+                first = false;
+            }
         }
+
         encStrBufCat(runtime, part, GT);
         return part;
     }
 
+    private boolean appendInstanceVariable(ThreadContext context, RubyString part, VariableAccessor accessor, String name, boolean first, Ruby runtime) {
+        Object value = accessor.get(this);
+        if (!(value instanceof IRubyObject)) return true;
+        RubySymbol symbol = asSymbol(context, name);
+        if (!symbol.validInstanceVariableName()) return true;
+
+        IRubyObject obj = (IRubyObject) value;
+
+        if (!first) encStrBufCat(runtime, part, COMMA);
+        encStrBufCat(runtime, part, SPACE);
+        // FIXME: bytelist_love: EPICLY wrong but something in MRI gets around identifiers of arbitrary encoding.
+        encStrBufCat(runtime, part, symbol.asString().encode(context, encodingService(context).convertEncodingToRubyEncoding(part.getEncoding())).asString().getByteList());
+        encStrBufCat(runtime, part, EQUALS);
+        encStrBufCat(runtime, part, sites(context).inspect.call(context, obj, obj).convertToString().getByteList());
+        return false;
+    }
+
     // Methods of the Object class (rb_obj_*):
 
 
@@ -1695,8 +1734,10 @@ public void forEachInstanceVariable(BiConsumer<String, IRubyObject> accessor) {
     }
 
     private void raiseFrozenError() throws RaiseException {
-        if (this instanceof RubyModule) {
-            throw getRuntime().newFrozenError("class/module ", this);
+        if (this instanceof RubyClass) {
+            throw getRuntime().newFrozenError("Class", this);
+        } else if (this instanceof RubyModule) {
+            throw getRuntime().newFrozenError("Module", this);
         } else {
             throw getRuntime().newFrozenError(this);
         }