fix: use RFC 5987 Content-Disposition for allzip and download-by-handle

Ports the allzip fix from customer/zcu-data (#1267) to dtq-dev and aligns the
fork's own endpoints with the encoding vanilla now uses.

The allzip endpoint still built its header with a bare
`attachment;filename="<name>"`, so item names with diacritics reached the
browser mangled and names containing a double quote closed the quoted-string
early (ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION).

MetadataBitstreamController and BitstreamByHandleRestController have no
counterpart upstream, so each carries its own private copy of vanilla's
createFallbackAsciiName / createEncodedUtf8Name rather than a shared fork
utility. Copying keeps every endpoint tracking upstream behaviour and adds no
fork-invented API to maintain. HttpHeadersInitializer stays byte-identical to
vanilla and keeps its own copy for the same reason.

One deliberate deviation from vanilla, marked in both copies: the ASCII
fallback escapes \ and ". Vanilla omits this, so a name containing a quote
closes the quoted-string early — exactly the bug #1267 was raised for.

Because the fallback now transliterates instead of blanking out,
BitstreamByHandleRestControllerIT expects "Media (3).jfif" where it used to
expect "M_di_ (3).jfif".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: milanmajchrak

dspace-server-webapp/src/main/java/org/dspace/app/rest/BitstreamByHandleRestController.java

@@ -15,6 +15,7 @@
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
+import java.text.Normalizer;
 import java.util.List;
 import java.util.Objects;
 import javax.servlet.http.HttpServletRequest;
@@ -279,25 +280,50 @@ private void redirectToS3DownloadUrl(String bitName, String bitInternalId,
     }
 
     /**
-     * Build a Content-Disposition header value using RFC 5987 encoding.
-     * Includes both {@code filename} (ASCII fallback) and {@code filename*}
-     * (UTF-8 percent-encoded) so that curl -J and browsers can save files
-     * with non-ASCII characters in the name correctly.
-     *
-     * @param name the original filename
-     * @return the Content-Disposition header value
+     * Build the Content-Disposition value the way vanilla's HttpHeadersInitializer does: an ASCII
+     * fallback in {@code filename} for clients that predate RFC 5987, plus the real UTF-8 name in
+     * {@code filename*} for everyone else. This endpoint has no upstream counterpart, so the logic
+     * is copied from vanilla rather than shared, to keep it tracking upstream's behaviour.
+     * curl -J on Windows cannot create files with non-ASCII characters from a raw UTF-8 header,
+     * which is why this endpoint needs it too.
      */
     private String buildContentDisposition(String name) {
-        // RFC 5987 percent-encoding for filename*
-        String encoded = URLEncoder.encode(name, StandardCharsets.UTF_8)
-                .replace("+", "%20");
-        // ASCII fallback: replace non-ASCII chars with underscore, escape quotes.
-        // Modern clients use filename* (RFC 5987 / RFC 6266) with real UTF-8 name.
-        String asciiFallback = name.replaceAll("[^\\x20-\\x7E]", "_")
+        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                createFallbackAsciiName(name), createEncodedUtf8Name(name));
+    }
+
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        // Deviates from vanilla by escaping \ and ": the value is a quoted-string, and a name
+        // containing a quote closes it early. That is the bug #1267 fixed; vanilla still has it.
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "")
                 .replace("\\", "\\\\")
                 .replace("\"", "\\\"");
-        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
-                asciiFallback, encoded);
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        return URLEncoder.encode(originalFilename, StandardCharsets.UTF_8).replace("+", "%20");
     }
 
     /**

dspace-server-webapp/src/main/java/org/dspace/app/rest/MetadataBitstreamController.java

@@ -11,7 +11,10 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
+import java.text.Normalizer;
 import java.util.List;
 import java.util.Objects;
 import java.util.UUID;
@@ -115,7 +118,7 @@ public void downloadFileZip(@PathVariable UUID uuid, @RequestParam("handleId") S
         // This bitstream is used to get it's item in the statistics tracker
         Bitstream bitstreamForStatistics = null;
         name = item.getName() + ".zip";
-        response.setHeader(HttpHeaders.CONTENT_DISPOSITION, String.format("attachment;filename=\"%s\"", name));
+        response.setHeader(HttpHeaders.CONTENT_DISPOSITION, buildContentDisposition(name));
         response.setContentType("application/zip");
         List<Bundle> bundles = item.getBundles("ORIGINAL");
 
@@ -143,4 +146,49 @@ public void downloadFileZip(@PathVariable UUID uuid, @RequestParam("handleId") S
         matomoBitstreamTracker.trackBitstreamDownload(context, request, bitstreamForStatistics, true);
         response.getOutputStream().flush();
     }
+
+    /**
+     * Build the Content-Disposition value the way vanilla's HttpHeadersInitializer does: an ASCII
+     * fallback in {@code filename} for clients that predate RFC 5987, plus the real UTF-8 name in
+     * {@code filename*} for everyone else. This endpoint has no upstream counterpart, so the logic
+     * is copied from vanilla rather than shared, to keep it tracking upstream's behaviour.
+     */
+    private String buildContentDisposition(String name) {
+        return String.format("attachment; filename=\"%s\"; filename*=UTF-8''%s",
+                createFallbackAsciiName(name), createEncodedUtf8Name(name));
+    }
+
+    /**
+     * Creates a safe ASCII-only fallback filename by removing diacritics (accents)
+     * and replacing any remaining non-ASCII characters.
+     * E.g., "ä-ö-é.pdf" becomes "a-o-e.pdf".
+     * @param originalFilename The original filename.
+     * @return A string containing only ASCII characters.
+     */
+    private String createFallbackAsciiName(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        String normalized = Normalizer.normalize(originalFilename, Normalizer.Form.NFD);
+        String withoutAccents = normalized.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
+        // Deviates from vanilla by escaping \ and ": the value is a quoted-string, and an item name
+        // containing a quote closes it early. That is the bug #1267 fixed; vanilla still has it.
+        return withoutAccents.replaceAll("[^\\x00-\\x7F]", "")
+                .replace("\\", "\\\\")
+                .replace("\"", "\\\"");
+    }
+
+    /**
+     * Creates a percent-encoded UTF-8 filename according to RFC 5987.
+     * This is for the `filename*` parameter.
+     * E.g., "ä ö é.pdf" becomes "%C3%A4%20%C3%B6%20%C3%A9.pdf".
+     * @param originalFilename The original filename.
+     * @return A percent-encoded string.
+     */
+    private String createEncodedUtf8Name(String originalFilename) {
+        if (originalFilename == null) {
+            return "";
+        }
+        return URLEncoder.encode(originalFilename, StandardCharsets.UTF_8).replace("+", "%20");
+    }
 }

dspace-server-webapp/src/test/java/org/dspace/app/rest/BitstreamByHandleRestControllerIT.java

@@ -260,8 +260,8 @@ public void downloadBitstreamByHandleUtf8Filename() throws Exception {
                         + "/M%C3%A9di%C3%A1%20(3).jfif")))
                 .andExpect(status().isOk())
                 .andExpect(header().string(HttpHeaders.CONTENT_DISPOSITION,
-                        // ASCII fallback replaces non-ASCII with underscore; filename* has UTF-8 encoding
-                        equalTo("attachment; filename=\"M_di_ (3).jfif\"; "
+                        // ASCII fallback transliterates the diacritics away; filename* keeps the real name
+                        equalTo("attachment; filename=\"Media (3).jfif\"; "
                                 + "filename*=UTF-8''M%C3%A9di%C3%A1%20%283%29.jfif")))
                 .andExpect(content().string(bitstreamContent));
     }

dspace-server-webapp/src/test/java/org/dspace/app/rest/MetadataBitstreamControllerIT.java

@@ -9,6 +9,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 import java.io.ByteArrayInputStream;
@@ -104,4 +105,62 @@ public void downloadAllZip() throws Exception {
         assertEquals(Set.of(bts.getName()), entries.keySet());
         assertEquals(BITSTREAM_CONTENT, entries.get(bts.getName()));
     }
+
+    @Test
+    public void downloadAllZipWithDoubleQuotesInItemName() throws Exception {
+        context.turnOffAuthorisationSystem();
+
+        // Double quotes in the name used to close the header's quoted-string early, which browsers
+        // reported as ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION.
+        Item itemWithQuotes = ItemBuilder.createItem(context, col)
+                .withTitle("Supported data for manuscript \"Thermally-induced evolution\"")
+                .withAuthor(AUTHOR)
+                .build();
+
+        try (InputStream is = IOUtils.toInputStream("QuotedItemContent", CharEncoding.UTF_8)) {
+            BitstreamBuilder.createBitstream(context, itemWithQuotes, is)
+                    .withName("data.csv")
+                    .withMimeType("text/csv")
+                    .build();
+        }
+        context.restoreAuthSystemState();
+
+        String token = getAuthToken(admin.getEmail(), password);
+        getClient(token).perform(get(METADATABITSTREAM_ENDPOINT + "/" + itemWithQuotes.getID() +
+                        "/" + ALL_ZIP_PATH).param(HANDLE_PARAM, itemWithQuotes.getHandle()))
+                .andExpect(status().isOk())
+                .andExpect(header().string("Content-Disposition",
+                        "attachment; filename=\"Supported data for manuscript"
+                        + " \\\"Thermally-induced evolution\\\".zip\";"
+                        + " filename*=UTF-8''Supported%20data%20for%20manuscript"
+                        + "%20%22Thermally-induced%20evolution%22.zip"));
+    }
+
+    @Test
+    public void downloadAllZipWithNonAsciiItemName() throws Exception {
+        context.turnOffAuthorisationSystem();
+
+        Item itemWithDiacritics = ItemBuilder.createItem(context, col)
+                .withTitle("Příliš žluťoučký kůň")
+                .withAuthor(AUTHOR)
+                .build();
+
+        try (InputStream is = IOUtils.toInputStream("DiacriticsContent", CharEncoding.UTF_8)) {
+            BitstreamBuilder.createBitstream(context, itemWithDiacritics, is)
+                    .withName("file.txt")
+                    .withMimeType("text/plain")
+                    .build();
+        }
+        context.restoreAuthSystemState();
+
+        String token = getAuthToken(admin.getEmail(), password);
+        getClient(token).perform(get(METADATABITSTREAM_ENDPOINT + "/" + itemWithDiacritics.getID() +
+                        "/" + ALL_ZIP_PATH).param(HANDLE_PARAM, itemWithDiacritics.getHandle()))
+                .andExpect(status().isOk())
+                // fallback transliterates the diacritics away; filename* carries the real name
+                .andExpect(header().string("Content-Disposition",
+                        "attachment; filename=\"Prilis zlutoucky kun.zip\";"
+                        + " filename*=UTF-8''P%C5%99%C3%ADli%C5%A1%20%C5%BElu%C5%A5ou%C4%8Dk%C3%BD"
+                        + "%20k%C5%AF%C5%88.zip"));
+    }
 }