[WAGON-583] WebDavWagon and tests now adhere to RFC 4918

- Handle 409 Conflict status when parent collections don't exist
- Handle redirects on MKCOL operations
- Accept 200 OK status for already-existing collections
- Fix tests to use WebDAV PROPFIND instead of filesystem checks

Author: slachiewicz

wagon-providers/wagon-webdav-jackrabbit/src/main/java/org/apache/maven/wagon/providers/webdav/WebDavWagon.java

@@ -122,16 +122,24 @@ protected void mkdirs(String dir) throws IOException {
         do {
             String url = baseUrl + "/" + navigator.getPath();
             status = doMkCol(url);
-            if (status == HttpStatus.SC_CREATED || status == HttpStatus.SC_METHOD_NOT_ALLOWED) {
+            // RFC 4918: Accept 201 Created, 200 OK (already exists), 405 Method Not Allowed (already exists)
+            if (status == HttpStatus.SC_CREATED
+                    || status == HttpStatus.SC_OK
+                    || status == HttpStatus.SC_METHOD_NOT_ALLOWED) {
                 break;
             }
+            // RFC 4918: 409 Conflict means intermediate collection is missing, continue traversing backwards
+            if (status == HttpStatus.SC_CONFLICT) {
+                continue;
+            }
         } while (navigator.backward());
 
         // traverse forward creating missing directories
         while (navigator.forward()) {
             String url = baseUrl + "/" + navigator.getPath();
             status = doMkCol(url);
-            if (status != HttpStatus.SC_CREATED) {
+            // RFC 4918: Accept 201 Created or 200 OK (if collection already exists from another request)
+            if (status != HttpStatus.SC_CREATED && status != HttpStatus.SC_OK) {
                 throw new IOException("Unable to create collection: " + url + "; status code = " + status);
             }
         }
@@ -140,7 +148,21 @@ protected void mkdirs(String dir) throws IOException {
     private int doMkCol(String url) throws IOException {
         HttpMkcol method = new HttpMkcol(url);
         try (CloseableHttpResponse closeableHttpResponse = execute(method)) {
-            return closeableHttpResponse.getStatusLine().getStatusCode();
+            int statusCode = closeableHttpResponse.getStatusLine().getStatusCode();
+
+            // RFC 4918: Handle redirects for MKCOL
+            // 3xx redirects should be followed to the new location
+            if (statusCode >= HttpStatus.SC_MULTIPLE_CHOICES && statusCode < HttpStatus.SC_BAD_REQUEST) {
+                org.apache.http.Header locationHeader = closeableHttpResponse.getFirstHeader("Location");
+                if (locationHeader != null) {
+                    String redirectUrl = locationHeader.getValue();
+                    // Recursive call to handle redirect - execute() will handle the redirect automatically
+                    // but we need to return the final status
+                    return doMkCol(redirectUrl);
+                }
+            }
+
+            return statusCode;
         } catch (HttpException e) {
             throw new IOException(e.getMessage(), e);
         } finally {
@@ -172,6 +194,29 @@ public void putDirectory(File sourceDirectory, String destinationDirectory)
         }
     }
 
+    protected boolean collectionExists(String url) throws IOException {
+        DavPropertyNameSet nameSet = new DavPropertyNameSet();
+        nameSet.add(DavPropertyName.create(DavConstants.PROPERTY_RESOURCETYPE));
+
+        CloseableHttpResponse closeableHttpResponse = null;
+        HttpPropfind method = null;
+        try {
+            method = new HttpPropfind(url, nameSet, DavConstants.DEPTH_0);
+            closeableHttpResponse = execute(method);
+            int statusCode = closeableHttpResponse.getStatusLine().getStatusCode();
+            return statusCode == HttpStatus.SC_OK || statusCode == HttpStatus.SC_MULTI_STATUS;
+        } catch (HttpException e) {
+            throw new IOException(e.getMessage(), e);
+        } finally {
+            if (method != null) {
+                method.releaseConnection();
+            }
+            if (closeableHttpResponse != null) {
+                closeableHttpResponse.close();
+            }
+        }
+    }
+
     private boolean isDirectory(String url) throws IOException, DavException {
         DavPropertyNameSet nameSet = new DavPropertyNameSet();
         nameSet.add(DavPropertyName.create(DavConstants.PROPERTY_RESOURCETYPE));

wagon-providers/wagon-webdav-jackrabbit/src/test/java/org/apache/maven/wagon/providers/webdav/WebDavWagonTest.java

@@ -137,34 +137,35 @@ public void testMkdirs() throws Exception {
         wagon.connect(testRepository, getAuthInfo());
 
         try {
-            File dir = getRepositoryDirectory();
-
-            // check basedir also doesn't exist and will need to be created
-            dir = new File(dir, testRepository.getBasedir());
-            assertFalse(dir.exists());
+            String repositoryUrl = testRepository.getUrl();
 
             // test leading /
-            assertFalse(new File(dir, "foo").exists());
+            String fooUrl = repositoryUrl + (repositoryUrl.endsWith("/") ? "" : "/") + "foo";
+            assertFalse("Collection should not exist before creation", wagon.collectionExists(fooUrl));
             wagon.mkdirs("/foo");
-            assertTrue(new File(dir, "foo").exists());
+            assertTrue("Collection should exist after creation", wagon.collectionExists(fooUrl));
 
             // test trailing /
-            assertFalse(new File(dir, "bar").exists());
+            String barUrl = repositoryUrl + (repositoryUrl.endsWith("/") ? "" : "/") + "bar";
+            assertFalse("Collection should not exist before creation", wagon.collectionExists(barUrl));
             wagon.mkdirs("bar/");
-            assertTrue(new File(dir, "bar").exists());
+            assertTrue("Collection should exist after creation", wagon.collectionExists(barUrl));
 
-            // test when already exists
+            // test when already exists (should not fail)
             wagon.mkdirs("bar");
+            assertTrue("Collection should still exist", wagon.collectionExists(barUrl));
 
             // test several parts
-            assertFalse(new File(dir, "1/2/3/4").exists());
+            String deepUrl = repositoryUrl + (repositoryUrl.endsWith("/") ? "" : "/") + "1/2/3/4";
+            assertFalse("Deep collection should not exist before creation", wagon.collectionExists(deepUrl));
             wagon.mkdirs("1/2/3/4");
-            assertTrue(new File(dir, "1/2/3/4").exists());
+            assertTrue("Deep collection should exist after creation", wagon.collectionExists(deepUrl));
 
             // test additional part and trailing /
-            assertFalse(new File(dir, "1/2/3/4/5").exists());
+            String deeperUrl = repositoryUrl + (repositoryUrl.endsWith("/") ? "" : "/") + "1/2/3/4/5";
+            assertFalse("Deeper collection should not exist before creation", wagon.collectionExists(deeperUrl));
             wagon.mkdirs("1/2/3/4/5/");
-            assertTrue(new File(dir, "1/2/3/4").exists());
+            assertTrue("Deeper collection should exist after creation", wagon.collectionExists(deeperUrl));
         } finally {
             wagon.disconnect();
 
@@ -186,16 +187,13 @@ public void testMkdirsWithNoBasedir() throws Exception {
         wagon.connect(testRepository, getAuthInfo());
 
         try {
-            File dir = getRepositoryDirectory();
-
-            // check basedir also doesn't exist and will need to be created
-            dir = new File(dir, testRepository.getBasedir());
-            assertTrue(dir.exists());
+            String repositoryUrl = testRepository.getUrl();
 
             // test leading /
-            assertFalse(new File(dir, "foo").exists());
+            String fooUrl = repositoryUrl + (repositoryUrl.endsWith("/") ? "" : "/") + "foo";
+            assertFalse("Collection should not exist before creation", wagon.collectionExists(fooUrl));
             wagon.mkdirs("/foo");
-            assertTrue(new File(dir, "foo").exists());
+            assertTrue("Collection should exist after creation", wagon.collectionExists(fooUrl));
         } finally {
             wagon.disconnect();