fix utf-8 decoding of dataset/file names

Author: qqmyers

src/main/java/edu/harvard/iq/dataverse/api/Datasets.java

@@ -3095,7 +3095,7 @@ public Response addFileToDataset(@Context ContainerRequestContext crc,
              * under the hood in Jersey here. So this should be considered a practical rather than final fix.
              */
 
-            newFilename = contentDispositionHeader.getFileName();
+            newFilename = FileUtil.decodeFileName(contentDispositionHeader.getFileName());
             // Let's see if the form data part has the mime (content) type specified.
             // Note that we don't want to rely on formDataBodyPart.getMediaType() -
             // because that defaults to "text/plain" when no "Content-Type:" header is

src/main/java/edu/harvard/iq/dataverse/api/Files.java

@@ -286,7 +286,7 @@ public Response replaceFileInDataset(
                         "You must upload a file or provide a valid storageidentifier, filename, and mimetype.");
             }
         } else {
-            newFilename = contentDispositionHeader.getFileName();
+            newFilename = FileUtil.decodeFileName(contentDispositionHeader.getFileName());
             newFileContentType = formDataBodyPart.getMediaType().toString();
         }
 

src/test/java/edu/harvard/iq/dataverse/util/FileUtilTest.java

@@ -436,4 +436,12 @@ public void testSanitizeFileName() {
         assertEquals("withcomma", FileUtil.sanitizeFileName("with,comma"));
         assertEquals("with.txt", FileUtil.sanitizeFileName("with,\\?:;,.txt"));
     }
+
+    @Test
+    public void testDecodeFileName() {
+        // "test-á.txt" encoded as UTF-8 but interpreted as ISO-8859-1
+        String mangledName = "test-á.txt";
+        assertEquals("test-á.txt", FileUtil.decodeFileName(mangledName));
+        assertEquals(null, FileUtil.decodeFileName(null));
+    }
 }