Preserve UTF-8 encoding in headers upon IMAP FETCH

Author: chibenwa

mailbox/api/src/main/java/org/apache/james/mailbox/model/Header.java

@@ -22,7 +22,7 @@
  */
 package org.apache.james.mailbox.model;
 
-import static java.nio.charset.StandardCharsets.US_ASCII;
+import static java.nio.charset.StandardCharsets.UTF_8;
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
@@ -75,12 +75,12 @@ public String toString() {
 
     @Override
     public InputStream getInputStream() {
-        return new ByteArrayInputStream((name + ": " + value).getBytes(US_ASCII));
+        return new ByteArrayInputStream((name + ": " + value).getBytes(UTF_8));
     }
 
     @Override
     public Publisher<ByteBuffer> reactiveBytes() {
-        return Flux.just((name + ": " + value).getBytes(US_ASCII))
+        return Flux.just((name + ": " + value).getBytes(UTF_8))
             .map(ByteBuffer::wrap);
     }
 }

protocols/imap/src/main/java/org/apache/james/imap/processor/fetch/MimeBodyElement.java

@@ -19,6 +19,7 @@
 package org.apache.james.imap.processor.fetch;
 
 import static java.nio.charset.StandardCharsets.US_ASCII;
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.james.imap.api.ImapConstants.LINE_END_BYTES;
 
 import java.io.ByteArrayInputStream;
@@ -88,7 +89,7 @@ public InputStream getInputStream() throws IOException {
         for (Header header : headers) {
             out.write(header.getName().getBytes(US_ASCII));
             out.write(NAME_DELIMITER_BYTES);
-            out.write(header.getValue().getBytes(US_ASCII));
+            out.write(header.getValue().getBytes(UTF_8));
             out.write(LINE_END_BYTES);
         }
         // no empty line with CRLF for MIME headers. See IMAP-297