From 53b0271d654901c2fc2c89ad56fbf470d6988fe4 Mon Sep 17 00:00:00 2001
From: Peter Franzen <peter@myire.org>
Date: Thu, 15 May 2025 14:05:49 +0200
Subject: [PATCH 1/2] GH-3215: Sort the list of
 org.apache.parquet.format.Encoding created by
 org.apache.parquet.format.converter.ParquetMetadataConverter::toFormatEncodings

---
 .../format/converter/ParquetMetadataConverter.java |  4 +++-
 .../converter/TestParquetMetadataConverter.java    | 14 ++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java b/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
index 60150439a6..3597898c30 100644
--- a/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
+++ b/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
@@ -703,11 +703,13 @@ private void addRowGroup(
     rowGroups.add(rowGroup);
   }
 
-  private List<Encoding> toFormatEncodings(Set<org.apache.parquet.column.Encoding> encodings) {
+  // Visible for testing
+  List<Encoding> toFormatEncodings(Set<org.apache.parquet.column.Encoding> encodings) {
     List<Encoding> converted = new ArrayList<Encoding>(encodings.size());
     for (org.apache.parquet.column.Encoding encoding : encodings) {
       converted.add(getEncoding(encoding));
     }
+    Collections.sort(converted);
     return converted;
   }
 
diff --git a/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java b/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
index 264017a1f0..ae015e56bc 100644
--- a/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
+++ b/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
@@ -759,6 +759,20 @@ public void testEncodingsCache() {
     assertEquals("java.util.Collections$UnmodifiableSet", res3.getClass().getName());
   }
 
+  @Test
+  public void testEncodingsOrder() {
+    ParquetMetadataConverter parquetMetadataConverter = new ParquetMetadataConverter();
+
+    Set<org.apache.parquet.column.Encoding> columnEncodings =
+        new HashSet<>(Arrays.asList(org.apache.parquet.column.Encoding.values()));
+
+    // Assert that the encodings are returned in ascending ordinal order
+    List<org.apache.parquet.format.Encoding> formatEncodings = parquetMetadataConverter.toFormatEncodings(columnEncodings);
+    for (int i=1; i<formatEncodings.size(); i++) {
+      assertTrue(formatEncodings.get(i - 1).ordinal() < formatEncodings.get(i).ordinal());
+    }
+  }
+
   @Test
   public void testBinaryStatsV1() {
     testBinaryStats(StatsHelper.V1);

From bb392b1431aefa1d63eba4cf224d916f9b4c8c7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mikael=20Br=C3=A4nnstr=C3=B6m?= <mikael.brannstrom@ngm.se>
Date: Fri, 6 Mar 2026 09:45:25 +0100
Subject: [PATCH 2/2] GH-3215: Reformat test case to address format violations
 failures.

---
 .../format/converter/TestParquetMetadataConverter.java    | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java b/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
index ae015e56bc..e4851d8ec4 100644
--- a/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
+++ b/parquet-hadoop/src/test/java/org/apache/parquet/format/converter/TestParquetMetadataConverter.java
@@ -767,9 +767,11 @@ public void testEncodingsOrder() {
         new HashSet<>(Arrays.asList(org.apache.parquet.column.Encoding.values()));
 
     // Assert that the encodings are returned in ascending ordinal order
-    List<org.apache.parquet.format.Encoding> formatEncodings = parquetMetadataConverter.toFormatEncodings(columnEncodings);
-    for (int i=1; i<formatEncodings.size(); i++) {
-      assertTrue(formatEncodings.get(i - 1).ordinal() < formatEncodings.get(i).ordinal());
+    List<org.apache.parquet.format.Encoding> formatEncodings =
+        parquetMetadataConverter.toFormatEncodings(columnEncodings);
+    for (int i = 1; i < formatEncodings.size(); i++) {
+      assertTrue(formatEncodings.get(i - 1).ordinal()
+          < formatEncodings.get(i).ordinal());
     }
   }