From 76f5254a75de7c6e75502369cd53b8bc35e99d8a Mon Sep 17 00:00:00 2001
From: Dawid Weiss <dawid.weiss@carrotsearch.com>
Date: Tue, 10 Dec 2024 19:26:18 +0100
Subject: [PATCH] IndexInput.isLoaded seems to return false for mmap index
 inputs on Windows #14050 (#14053)

---
 .../lucene/store/MemorySegmentIndexInput.java       | 13 +++++++++++--
 .../lucene/tests/store/BaseDirectoryTestCase.java   |  6 +++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/lucene/core/src/java21/org/apache/lucene/store/MemorySegmentIndexInput.java b/lucene/core/src/java21/org/apache/lucene/store/MemorySegmentIndexInput.java
index 2fc9f6369b7..2424b53645b 100644
--- a/lucene/core/src/java21/org/apache/lucene/store/MemorySegmentIndexInput.java
+++ b/lucene/core/src/java21/org/apache/lucene/store/MemorySegmentIndexInput.java
@@ -27,6 +27,7 @@ import java.util.Objects;
 import java.util.Optional;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BitUtil;
+import org.apache.lucene.util.Constants;
 import org.apache.lucene.util.GroupVIntUtil;
 import org.apache.lucene.util.IOConsumer;
 
@@ -422,12 +423,20 @@ abstract class MemorySegmentIndexInput extends IndexInput
 
   @Override
   public Optional<Boolean> isLoaded() {
+    boolean isLoaded = true;
     for (MemorySegment seg : segments) {
       if (seg.isLoaded() == false) {
-        return Optional.of(Boolean.FALSE);
+        isLoaded = false;
+        break;
       }
     }
-    return Optional.of(Boolean.TRUE);
+
+    if (Constants.WINDOWS && isLoaded == false) {
+      // see https://github.com/apache/lucene/issues/14050
+      return Optional.empty();
+    }
+
+    return Optional.of(isLoaded);
   }
 
   @Override
diff --git a/lucene/test-framework/src/java/org/apache/lucene/tests/store/BaseDirectoryTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/tests/store/BaseDirectoryTestCase.java
index d8ec0529b5f..6defa5eb8c7 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/tests/store/BaseDirectoryTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/tests/store/BaseDirectoryTestCase.java
@@ -63,6 +63,7 @@ import org.apache.lucene.tests.util.LuceneTestCase;
 import org.apache.lucene.tests.util.TestUtil;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BitUtil;
+import org.apache.lucene.util.Constants;
 import org.apache.lucene.util.GroupVIntUtil;
 import org.apache.lucene.util.IOUtils;
 import org.apache.lucene.util.packed.PackedInts;
@@ -1667,7 +1668,10 @@ public abstract class BaseDirectoryTestCase extends LuceneTestCase {
           in = orig.slice("slice", startOffset, totalLength - startOffset);
         }
         var loaded = in.isLoaded();
-        if (FilterDirectory.unwrap(dir) instanceof MMapDirectory
+
+        if (Constants.WINDOWS) {
+          // On Windows, we temporarily don't care until this is fixed: #14050
+        } else if (FilterDirectory.unwrap(dir) instanceof MMapDirectory
             // direct IO wraps MMap but does not support isLoaded
             && !(dir.getClass().getName().contains("DirectIO"))) {
           assertTrue(loaded.isPresent());