Fix ZIP CRC regression in OffloadingOutputStream

src/main/java/org/codehaus/plexus/archiver/zip/ByteArrayOutputStream.java

@@ -262,7 +262,7 @@ public synchronized void reset() {
         } else {
             // Throw away old buffers
             currentBuffer = null;
-            int size = buffers.get(0).length;
+            int size = buffers.isEmpty() ? 1024 : buffers.get(0).length;
             buffers.clear();
             needNewBuffer(size);
             reuseBuffers = true;

src/main/java/org/codehaus/plexus/archiver/zip/ConcurrentJarCreator.java

@@ -23,6 +23,7 @@
 import java.io.SequenceInputStream;
 import java.io.UncheckedIOException;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.zip.Deflater;
 import java.util.zip.ZipEntry;
@@ -55,6 +56,8 @@ public class ConcurrentJarCreator {
 
     private final ParallelScatterZipCreator parallelScatterZipCreator;
 
+    private final ExecutorService es;
+
     private long zipCloseElapsed;
 
     private static class DeferredSupplier implements ScatterGatherBackingStoreSupplier {
@@ -118,8 +121,8 @@ public ConcurrentJarCreator(boolean compressAddedZips, int nThreads) throws IOEx
         manifest = createDeferred(defaultSupplier);
         directories = createDeferred(defaultSupplier);
         synchronousEntries = createDeferred(defaultSupplier);
-        parallelScatterZipCreator =
-                new ParallelScatterZipCreator(Executors.newFixedThreadPool(nThreads), defaultSupplier);
+        es = Executors.newFixedThreadPool(nThreads);
+        parallelScatterZipCreator = new ParallelScatterZipCreator(es, defaultSupplier);
     }
 
     /**
@@ -161,11 +164,15 @@ public void addArchiveEntry(
 
     public void writeTo(ZipArchiveOutputStream targetStream)
             throws IOException, ExecutionException, InterruptedException {
-        metaInfDir.writeTo(targetStream);
-        manifest.writeTo(targetStream);
-        directories.writeTo(targetStream);
-        synchronousEntries.writeTo(targetStream);
-        parallelScatterZipCreator.writeTo(targetStream);
+        try {
+            metaInfDir.writeTo(targetStream);
+            manifest.writeTo(targetStream);
+            directories.writeTo(targetStream);
+            synchronousEntries.writeTo(targetStream);
+            parallelScatterZipCreator.writeTo(targetStream);
+        } finally {
+            es.shutdown();
+        }
         long startAt = System.currentTimeMillis();
         targetStream.close();
         zipCloseElapsed = System.currentTimeMillis() - startAt;

src/main/java/org/codehaus/plexus/archiver/zip/DeferredScatterOutputStream.java

@@ -17,9 +17,10 @@
  */
 package org.codehaus.plexus.archiver.zip;
 
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
 import org.apache.commons.compress.parallel.ScatterGatherBackingStore;
 
@@ -48,9 +49,9 @@ public void closeForWriting() throws IOException {
 
     @Override
     public void close() throws IOException {
-        File file = dfos.getFile();
+        Path file = dfos.getOutputPath();
         if (file != null) {
-            file.delete();
+            Files.deleteIfExists(file);
         }
     }
 }

src/main/java/org/codehaus/plexus/archiver/zip/OffloadingOutputStream.java

@@ -113,7 +113,7 @@ protected OutputStream getStream() throws IOException {
     @Override
     protected void thresholdReached() throws IOException {
         outputPath = Files.createTempFile(prefix, suffix);
-        currentOutputStream = Streams.fileOutputStream(outputPath);
+        currentOutputStream = Streams.bufferedOutputStream(Files.newOutputStream(outputPath));
     }
 
     public InputStream getInputStream() throws IOException {
@@ -142,6 +142,10 @@ public byte[] getData() {
         return null;
     }
 
+    public Path getOutputPath() {
+        return outputPath;
+    }
+
     /**
      * Returns either the output file specified in the constructor or
      * the temporary file created or null.