fix(s3): guard ETag and version-id reads against missing headers

engine/extensions/storage-drivers/implementations/s3/src/main/java/com/dell/spt/storage/driver/coop/netty/http/s3/S3ResponseHandler.java

@@ -53,22 +53,31 @@ public S3ResponseHandler(final S3StorageDriver<I, O> driver, final boolean verif
 	@Override
 	protected final void handleResponseHeaders(final Channel channel, final O op, final HttpHeaders respHeaders) {
 		if (op instanceof PartialDataOperation && OpType.CREATE.equals(op.type())) {
-			// Capture part ETags for MPU write — needed for CompleteMultipartUpload XML body
-			final PartialDataOperation subTask = (PartialDataOperation) op;
+			// Capture part ETags for MPU write — needed for CompleteMultipartUpload XML body.
+			// On error responses the server omits the ETag header; skip recording in that case
+			// (the part will be retried, and the contextData map rejects null values).
 			final String eTag = respHeaders.get(HttpHeaderNames.ETAG);
-			final CompositeDataOperation mpuTask = subTask.parent();
-			final int partNum = subTask.partNumber() + 1;
-			mpuTask.put(Integer.toString(partNum), eTag);
-			// Capture per-part checksum value if the server echoed one back
-			if (checksumHeader != null) {
-				final String checksumVal = respHeaders.get(checksumHeader);
-				if (checksumVal != null) {
-					mpuTask.put(S3Api.KEY_PART_CHECKSUM_PREFIX + partNum, checksumVal);
+			if (eTag != null) {
+				final PartialDataOperation subTask = (PartialDataOperation) op;
+				final CompositeDataOperation mpuTask = subTask.parent();
+				final int partNum = subTask.partNumber() + 1;
+				mpuTask.put(Integer.toString(partNum), eTag);
+				// Capture per-part checksum value if the server echoed one back
+				if (checksumHeader != null) {
+					final String checksumVal = respHeaders.get(checksumHeader);
+					if (checksumVal != null) {
+						mpuTask.put(S3Api.KEY_PART_CHECKSUM_PREFIX + partNum, checksumVal);
+					}
 				}
 			}
 		}
 		if (versioningEnabled) {
-			op.item().name(op.item().name() + "~" + respHeaders.get("x-amz-version-id"));
+			// Skip on error responses (no x-amz-version-id header); otherwise the literal
+			// string "null" gets appended to the item name, compounding on each retry.
+			final String versionId = respHeaders.get("x-amz-version-id");
+			if (versionId != null) {
+				op.item().name(op.item().name() + "~" + versionId);
+			}
 		}
 	}
 

engine/extensions/storage-drivers/implementations/s3/src/test/java/com/dell/spt/storage/driver/coop/netty/http/s3/S3ResponseHandlerMpuPartTest.java

@@ -0,0 +1,63 @@
+package com.dell.spt.storage.driver.coop.netty.http.s3;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.dell.spt.base.item.DataItemImpl;
+import com.dell.spt.base.item.op.OpType;
+import com.dell.spt.base.item.op.composite.data.CompositeDataOperationImpl;
+import com.dell.spt.base.item.op.data.DataOperationImpl;
+import com.dell.spt.base.item.op.partial.data.PartialDataOperationImpl;
+import com.dell.spt.base.storage.Credential;
+
+import io.netty.handler.codec.http.DefaultHttpHeaders;
+import io.netty.handler.codec.http.HttpHeaders;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Regression tests covering response-header handling on error responses, where the
+ * server omits headers the success path would normally provide (ETag for MPU parts,
+ * x-amz-version-id when versioning is enabled). Both branches must tolerate the
+ * missing headers without throwing or silently corrupting operation state.
+ */
+final class S3ResponseHandlerMpuPartTest {
+
+	private static final long PART_SIZE = 10L * 1024 * 1024;
+	private static final long ITEM_SIZE = 20L * 1024 * 1024;
+
+	@Test
+	void handleResponseHeadersDoesNotThrowWhenPartResponseHasNoETag() {
+		final var handler = new S3ResponseHandler<DataItemImpl, PartialDataOperationImpl<DataItemImpl>>(
+						null, false, false, null);
+
+		final var partItem = new DataItemImpl(0L, PART_SIZE);
+		final var parentItem = new DataItemImpl(0L, ITEM_SIZE);
+		final var parent = new CompositeDataOperationImpl<DataItemImpl>(
+						0, OpType.CREATE, parentItem, null, "/streaming/20MB/63/", Credential.NONE,
+						null, 0, PART_SIZE);
+		final var partOp = new PartialDataOperationImpl<DataItemImpl>(
+						0, OpType.CREATE, partItem, null, "/streaming/20MB/63/", Credential.NONE,
+						0, parent);
+
+		final HttpHeaders emptyHeaders = new DefaultHttpHeaders();
+
+		assertDoesNotThrow(() -> handler.handleResponseHeaders(null, partOp, emptyHeaders));
+	}
+
+	@Test
+	void handleResponseHeadersDoesNotCorruptItemNameWhenVersionHeaderMissing() {
+		final var handler = new S3ResponseHandler<DataItemImpl, DataOperationImpl<DataItemImpl>>(
+						null, false, true, null);
+
+		final var item = new DataItemImpl("foo", 0L, ITEM_SIZE);
+		final var op = new DataOperationImpl<DataItemImpl>(
+						0, OpType.CREATE, item, null, "/bucket/", Credential.NONE, null, 0);
+
+		final HttpHeaders emptyHeaders = new DefaultHttpHeaders();
+
+		handler.handleResponseHeaders(null, op, emptyHeaders);
+
+		assertEquals("foo", item.name());
+	}
+}