From 6f3c61199448883e4e1c99c21ee899bf868295af Mon Sep 17 00:00:00 2001
From: charliechen <jchen264@uw.edu>
Date: Fri, 28 Aug 2026 16:39:09 -0700
Subject: [PATCH] Delta: Use POSIX separator for data file paths

Build migrated Delta data file locations with the URI separator so paths remain valid when the migration runs on Windows.

Generated-by: Codex
---
 .../iceberg/delta/BaseSnapshotDeltaLakeTableAction.java  | 5 ++---
 .../delta/TestBaseSnapshotDeltaLakeTableAction.java      | 9 +++++++++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/delta-lake/src/main/java/org/apache/iceberg/delta/BaseSnapshotDeltaLakeTableAction.java b/delta-lake/src/main/java/org/apache/iceberg/delta/BaseSnapshotDeltaLakeTableAction.java
index 69bbaed71997..b9970b95ffe0 100644
--- a/delta-lake/src/main/java/org/apache/iceberg/delta/BaseSnapshotDeltaLakeTableAction.java
+++ b/delta-lake/src/main/java/org/apache/iceberg/delta/BaseSnapshotDeltaLakeTableAction.java
@@ -24,7 +24,6 @@
 import io.delta.standalone.actions.AddFile;
 import io.delta.standalone.actions.RemoveFile;
 import io.delta.standalone.exceptions.DeltaStandaloneException;
-import java.io.File;
 import java.net.URI;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
@@ -448,13 +447,13 @@ private void tagCurrentSnapshot(long deltaVersion, Transaction transaction) {
    *     (either absolute or relative)
    * @param tableRoot the root path of the delta table
    */
-  private static String getFullFilePath(String path, String tableRoot) {
+  static String getFullFilePath(String path, String tableRoot) {
     URI dataFileUri = URI.create(path);
     String decodedPath = URLDecoder.decode(path, StandardCharsets.UTF_8);
     if (dataFileUri.isAbsolute()) {
       return decodedPath;
     } else {
-      return tableRoot + File.separator + decodedPath;
+      return tableRoot + "/" + decodedPath;
     }
   }
 }
diff --git a/delta-lake/src/test/java/org/apache/iceberg/delta/TestBaseSnapshotDeltaLakeTableAction.java b/delta-lake/src/test/java/org/apache/iceberg/delta/TestBaseSnapshotDeltaLakeTableAction.java
index f77ce441067e..c37c99e17a4e 100644
--- a/delta-lake/src/test/java/org/apache/iceberg/delta/TestBaseSnapshotDeltaLakeTableAction.java
+++ b/delta-lake/src/test/java/org/apache/iceberg/delta/TestBaseSnapshotDeltaLakeTableAction.java
@@ -18,6 +18,7 @@
  */
 package org.apache.iceberg.delta;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import java.io.File;
@@ -99,6 +100,14 @@ public void testDeltaTableNotExist() {
             "Delta Lake table does not exist at the given location: %s", sourceTableLocation);
   }
 
+  @Test
+  public void fullFilePathUsesUriSeparator() {
+    assertThat(
+            BaseSnapshotDeltaLakeTableAction.getFullFilePath(
+                "data/file.parquet", "s3://bucket/table"))
+        .isEqualTo("s3://bucket/table/data/file.parquet");
+  }
+
   private static class TestCatalog extends BaseMetastoreCatalog {
     TestCatalog() {}