Azure: Fix ADLSInputStream.readTail for length over file size

azure/src/main/java/org/apache/iceberg/azure/adlsv2/ADLSInputStream.java

@@ -189,7 +189,7 @@ public int readTail(byte[] buffer, int offset, int length) throws IOException {
     if (this.fileSize == null) {
       this.fileSize = fileClient.getProperties().getFileSize();
     }
-    long readStart = fileSize - length;
+    long readStart = Math.max(0, fileSize - length);
 
     try (InputStream inputStream = openRange(new FileRange(readStart)).getInputStream()) {
       return IOUtil.readRemaining(inputStream, buffer, offset, length);

azure/src/test/java/org/apache/iceberg/azure/adlsv2/TestADLSInputStream.java

@@ -123,4 +123,27 @@ void testReadTailClosesTheStream() throws IOException {
 
     verify(inputStream).close();
   }
+
+  @Test
+  void testReadTailLengthLargerThanFileSize() throws IOException {
+    byte[] data = new byte[] {1, 2, 3};
+    InputStream byteStream = new ByteArrayInputStream(data);
+    InternalDataLakeFileOpenInputStreamResult openInputStreamResult =
+        new InternalDataLakeFileOpenInputStreamResult(byteStream, mock());
+    when(fileClient.openInputStream(any())).thenReturn(openInputStreamResult);
+
+    try (ADLSInputStream in =
+        new ADLSInputStream(
+            "abfs://container@account.dfs.core.windows.net/path/to/file",
+            fileClient,
+            3L,
+            mock(),
+            MetricsContext.nullMetrics())) {
+
+      byte[] actual = new byte[10];
+      int bytesRead = in.readTail(actual, 0, 10);
+      assertThat(bytesRead).isEqualTo(3);
+      assertThat(Arrays.copyOfRange(actual, 0, bytesRead)).isEqualTo(data);
+    }
+  }
 }