Do not inherit ALLOW_DUPLICATE_ENTRIES

io/src/main/java/io/smallrye/common/io/archive/ArchiveBuilder.java

@@ -1221,7 +1221,8 @@ public ArchiveBuilder addArchive(String name) throws IOException {
      * or the outer builder can be closed.
      * <p>
      * {@link ZipOption#ZIP64} applies to the outer entry (reserving ZIP64 space in the outer local
-     * file header). The inner builder inherits the same options as its defaults.
+     * file header). The inner builder inherits the same options as its defaults, with the exception of
+     * {@link ZipOption#ALLOW_DUPLICATE_ENTRIES}.
      *
      * @param name the entry name for the nested archive (must not be {@code null})
      * @param options the options; may contain {@link ZipOption} values
@@ -1272,7 +1273,8 @@ public ArchiveBuilder addArchive(String name, FileAttribute<?>... attrs) throws
      * or the outer builder can be closed.
      * <p>
      * {@link ZipOption#ZIP64} applies to the outer entry (reserving ZIP64 space in the outer local
-     * file header). The inner builder inherits the same options as its defaults.
+     * file header). The inner builder inherits the same options as its defaults, with the exception of
+     * {@link ZipOption#ALLOW_DUPLICATE_ENTRIES}.
      * {@link ZipOption#DEFLATED} is permitted here (unlike {@code addBufferedEntry}) and sets
      * the inner builder's default compression method; the outer entry is always STORED.
      * <p>
@@ -1307,7 +1309,7 @@ public ArchiveBuilder addArchive(String name, Collection<? extends OpenOption> o
         // which triggers the close action for CRC/LFH patching on the outer entry
         return new ArchiveBuilder(nested, nested.filePosition(),
                 innerMethod == PARSED_NO_METHOD ? METHOD_DEFLATE : innerMethod, zip64,
-                (parsed & PARSED_ALLOW_DUPLICATE_ENTRIES) != 0 || allowDuplicateEntries);
+                (parsed & PARSED_ALLOW_DUPLICATE_ENTRIES) != 0);
     }
 
     // ── Raw data methods ────────────────────────────────────────────────

io/src/test/java/io/smallrye/common/io/archive/ArchiveBuilderTests.java

@@ -2072,4 +2072,33 @@ public void testDuplicateNestedArchiveBlockedByDefault() throws Exception {
             });
         }
     }
+
+    /**
+     * Test that {@link ZipOption#ALLOW_DUPLICATE_ENTRIES} is not inherited by a nested archive,
+     * but can be specified explicitly on the nested archive if desired.
+     *
+     * @throws Exception if an unexpected error occurs
+     */
+    @Test
+    public void testDuplicateOptionNotInheritedByNestedArchive() throws Exception {
+        Path file = tempDir.resolve("duplicate-nested-not-inherited.zip");
+        // Outer archive has duplicates allowed
+        try (ArchiveBuilder builder = ArchiveBuilder.open(file, ZipOption.ALLOW_DUPLICATE_ENTRIES)) {
+            // Nested archive does NOT have duplicate options specified, so it should NOT allow duplicates
+            try (ArchiveBuilder inner = builder.addArchive("inner1.jar")) {
+                inner.addEntry("foo.txt", "foo".getBytes(StandardCharsets.UTF_8));
+                assertThrows(IllegalArgumentException.class, () -> {
+                    inner.addEntry("foo.txt", "bar".getBytes(StandardCharsets.UTF_8));
+                });
+            }
+
+            // Nested archive explicitly has duplicate options specified, so it should allow duplicates
+            try (ArchiveBuilder inner = builder.addArchive("inner2.jar", ZipOption.ALLOW_DUPLICATE_ENTRIES)) {
+                inner.addEntry("foo.txt", "foo".getBytes(StandardCharsets.UTF_8));
+                assertDoesNotThrow(() -> {
+                    inner.addEntry("foo.txt", "bar".getBytes(StandardCharsets.UTF_8));
+                });
+            }
+        }
+    }
 }