Fix AbstractArchiver.getFiles() to return forward slashes for ZIP-based archivers (#392)

* Override getFiles() in AbstractZipArchiver to normalize paths to forward slashes

Co-authored-by: slachiewicz <6705942+slachiewicz@users.noreply.github.com>

---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: slachiewicz <6705942+slachiewicz@users.noreply.github.com>

Author: Copilot

src/main/java/org/codehaus/plexus/archiver/AbstractArchiver.java

@@ -616,6 +616,23 @@ private static void closeQuietlyIfCloseable(Object resource) {
         }
     }
 
+    /**
+     * Returns a map of the files that have been added to the archive.
+     * <p>
+     * Note: The entry names in the map use platform-specific path separators
+     * (e.g., backslashes on Windows, forward slashes on Unix). For ZIP archivers,
+     * the actual archive entries will use forward slashes as required by the ZIP
+     * specification, but this map returns names as they were added.
+     * </p>
+     * <p>
+     * For ZIP-based archivers (ZipArchiver, JarArchiver, etc.), use the overridden
+     * implementation which normalizes paths to forward slashes to match the actual
+     * ZIP entry names.
+     * </p>
+     *
+     * @return A map where keys are entry names and values are the corresponding ArchiveEntry objects.
+     * @deprecated Use {@link #getResources()} instead.
+     */
     @Override
     @Deprecated
     public Map<String, ArchiveEntry> getFiles() {

src/main/java/org/codehaus/plexus/archiver/Archiver.java

@@ -260,6 +260,16 @@ void addArchivedFileSet(@Nonnull File archiveFile, String prefix, String[] inclu
     ResourceIterator getResources() throws ArchiverException;
 
     /**
+     * Returns a map of the files that have been added to the archive.
+     * <p>
+     * Note: The entry names in the map may use platform-specific path separators
+     * in the base implementation. However, archive format-specific implementations
+     * (such as ZIP-based archivers) should normalize paths according to their format
+     * requirements. For example, ZIP archivers normalize to forward slashes as required
+     * by the ZIP file specification.
+     * </p>
+     *
+     * @return A map where keys are entry names and values are the corresponding ArchiveEntry objects.
      * @deprecated Use {@link #getResources()}
      */
     @Deprecated

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

@@ -27,8 +27,10 @@
 import java.nio.file.attribute.FileTime;
 import java.util.Calendar;
 import java.util.Deque;
+import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.Locale;
+import java.util.Map;
 import java.util.TimeZone;
 import java.util.concurrent.ExecutionException;
 import java.util.zip.CRC32;
@@ -564,6 +566,29 @@ protected boolean createEmptyZip(File zipFile) throws ArchiverException {
         return true;
     }
 
+    /**
+     * Returns a map of the files that have been added to the archive.
+     * This method is overridden to normalize path separators to forward slashes,
+     * as required by the ZIP file format specification.
+     *
+     * @return A map where keys are entry names with forward slashes as separators,
+     *         and values are the corresponding ArchiveEntry objects.
+     * @deprecated Use {@link #getResources()} instead.
+     */
+    @Override
+    @Deprecated
+    public Map<String, ArchiveEntry> getFiles() {
+        Map<String, ArchiveEntry> files = super.getFiles();
+        Map<String, ArchiveEntry> normalizedFiles = new HashMap<>();
+
+        for (Map.Entry<String, ArchiveEntry> entry : files.entrySet()) {
+            String normalizedPath = entry.getKey().replace(File.separatorChar, '/');
+            normalizedFiles.put(normalizedPath, entry.getValue());
+        }
+
+        return normalizedFiles;
+    }
+
     /**
      * Do any clean up necessary to allow this instance to be used again.
      * <p>

src/test/java/org/codehaus/plexus/archiver/zip/ZipArchiverTest.java

@@ -52,6 +52,7 @@
 import org.apache.commons.compress.archivers.zip.ZipExtraField;
 import org.apache.commons.compress.archivers.zip.ZipFile;
 import org.apache.commons.io.input.BoundedInputStream;
+import org.codehaus.plexus.archiver.ArchiveEntry;
 import org.codehaus.plexus.archiver.Archiver;
 import org.codehaus.plexus.archiver.ArchiverException;
 import org.codehaus.plexus.archiver.BasePlexusArchiverTest;
@@ -857,4 +858,38 @@ private long toLocalTimeZone(long timestamp) {
             return 0L;
         }
     }
+
+    /**
+     * Test that getFiles() returns entry names with forward slashes (not platform-specific separators)
+     * as required by the ZIP file specification.
+     */
+    @Test
+    void testGetFilesReturnsForwardSlashes() throws Exception {
+        File zipFile = getTestFile("target/output/test-getfiles-slashes.zip");
+        ZipArchiver archiver = getZipArchiver(zipFile);
+
+        // Add files with nested directory structure
+        File pomFile = new File("pom.xml");
+        archiver.addFile(pomFile, "dir1/dir2/pom.xml");
+        archiver.addFile(pomFile, "another/nested/path/file.xml");
+
+        // Get the files map BEFORE creating the archive
+        Map<String, ArchiveEntry> files = archiver.getFiles();
+
+        // Verify all entry names use forward slashes
+        for (String entryName : files.keySet()) {
+            assertFalse(entryName.contains("\\"), "Entry name should not contain backslashes, but got: " + entryName);
+            assertTrue(
+                    entryName.contains("/") || !entryName.contains(File.separator),
+                    "Entry name should use forward slashes as separator: " + entryName);
+        }
+
+        // Verify specific entries exist with correct format
+        assertTrue(files.containsKey("dir1/dir2/pom.xml"), "Should contain dir1/dir2/pom.xml");
+        assertTrue(files.containsKey("another/nested/path/file.xml"), "Should contain another/nested/path/file.xml");
+
+        // Create the archive to ensure it's valid
+        archiver.createArchive();
+        assertTrue(zipFile.exists());
+    }
 }