From 317681b5638045e66f56307b55e10717bd889908 Mon Sep 17 00:00:00 2001
From: "Keith W. Campbell" <keithc@ca.ibm.com>
Date: Tue, 25 Jul 2023 16:05:34 -0400
Subject: [PATCH] Back-port fix for ModuleDescriptor.hashCode()

* 8275509: ModuleDescriptor.hashCode isn't reproducible across builds
* 8290041: ModuleDescriptor.hashCode is inconsistent

Signed-off-by: Keith W. Campbell <keithc@ca.ibm.com>
---
 .../java/lang/module/ModuleDescriptor.java    | 20 +++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java b/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java
index fa359348f6c..f9ebfe1559d 100644
--- a/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java
+++ b/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java
@@ -333,7 +333,7 @@ public boolean equals(Object ob) {
          */
         @Override
         public int hashCode() {
-            int hash = name.hashCode() * 43 + mods.hashCode();
+            int hash = name.hashCode() * 43 + modsHashCode(mods);
             if (compiledVersion != null)
                 hash = hash * 43 + compiledVersion.hashCode();
             if (rawCompiledVersion != null)
@@ -514,7 +514,7 @@ public int compareTo(Exports that) {
          */
         @Override
         public int hashCode() {
-            int hash = mods.hashCode();
+            int hash = modsHashCode(mods);
             hash = hash * 43 + source.hashCode();
             return hash * 43 + targets.hashCode();
         }
@@ -721,7 +721,7 @@ public int compareTo(Opens that) {
          */
         @Override
         public int hashCode() {
-            int hash = mods.hashCode();
+            int hash = modsHashCode(mods);
             hash = hash * 43 + source.hashCode();
             return hash * 43 + targets.hashCode();
         }
@@ -2283,7 +2283,7 @@ public int hashCode() {
         int hc = hash;
         if (hc == 0) {
             hc = name.hashCode();
-            hc = hc * 43 + Objects.hashCode(modifiers);
+            hc = hc * 43 + modsHashCode(modifiers);
             hc = hc * 43 + requires.hashCode();
             hc = hc * 43 + Objects.hashCode(packages);
             hc = hc * 43 + exports.hashCode();
@@ -2568,6 +2568,18 @@ private static <M> String toString(Set<M> mods, String what) {
                 .collect(Collectors.joining(" "));
     }
 
+    /**
+     * Generates and returns a hashcode for the enum instances. The returned hashcode
+     * is a value based on the {@link Enum#name() name} of each enum instance.
+     */
+    private static int modsHashCode(Iterable<? extends Enum<?>> enums) {
+        int h = 0;
+        for (Enum<?> e : enums) {
+            h += e.name().hashCode();
+        }
+        return h;
+    }
+
     private static <T extends Object & Comparable<? super T>>
     int compare(T obj1, T obj2) {
         if (obj1 != null) {