Extract MIME type fixup code to method MimeUtility.getMimeTypeForViewing()

src/com/fsck/k9/mail/internet/MimeUtility.java

@@ -1220,6 +1220,26 @@ public class MimeUtility {
 		return mimeType;
 	}
 
+    /**
+     * When viewing the attachment we want the MIME type to be as sensible as
+     * possible. So we fix it up if necessary.
+     *
+     * @param mimeType The original MIME type of the attachment.
+     * @param name The (file)name of the attachment.
+     *
+     * @return The best MIME type we can come up with.
+     */
+    public static String getMimeTypeForViewing(String mimeType, String name) {
+        if (DEFAULT_ATTACHMENT_MIME_TYPE.equalsIgnoreCase(mimeType)) {
+            // If the MIME type is the generic "application/octet-stream"
+            // we try to find a better one by looking at the file extension.
+            return getMimeTypeByExtension(name);
+        } else {
+            // Some messages contain wrong MIME types. See if we know better.
+            return canonicalizeMimeType(mimeType);
+        }
+    }
+
     private static Message getMessageFromPart(Part part) {
         while (part != null) {
             if (part instanceof Message)

src/com/fsck/k9/provider/AttachmentProvider.java

@@ -118,16 +118,7 @@ public class AttachmentProvider extends ContentProvider {
 
                 AttachmentInfo attachmentInfo = localStore.getAttachmentInfo(id);
                 if (FORMAT_VIEW.equals(format)) {
-                    // When viewing the attachment we want the MIME type to be
+                    return MimeUtility.getMimeTypeForViewing(attachmentInfo.type, attachmentInfo.name);
-                    // as sensible as possible. So we fix it up if necessary.
-                    if (MimeUtility.DEFAULT_ATTACHMENT_MIME_TYPE.equalsIgnoreCase(attachmentInfo.type)) {
-                        // If the MIME type is the generic "application/octet-stream"
-                        // we try to find a better one by looking at the file extension.
-                        return MimeUtility.getMimeTypeByExtension(attachmentInfo.name);
-                    } else {
-                        // Some messages contain wrong MIME types. See if we know better.
-                        return MimeUtility.canonicalizeMimeType(attachmentInfo.type);
-                    }
                 } else {
                     // When accessing the "raw" message we deliver the original MIME type.
                     return attachmentInfo.type;

src/com/fsck/k9/view/AttachmentView.java

@@ -78,10 +78,7 @@ public class AttachmentView extends FrameLayout {
             mListener = listener;
 
             size = Integer.parseInt(MimeUtility.getHeaderParameter(contentDisposition, "size"));
-            contentType = part.getMimeType();
+            contentType = MimeUtility.getMimeTypeForViewing(part.getMimeType(), name);
-            if (MimeUtility.DEFAULT_ATTACHMENT_MIME_TYPE.equalsIgnoreCase(contentType)) {
-                contentType = MimeUtility.getMimeTypeByExtension(name);
-            }
             TextView attachmentName = (TextView) findViewById(R.id.attachment_name);
             TextView attachmentInfo = (TextView) findViewById(R.id.attachment_info);
             ImageView attachmentIcon = (ImageView) findViewById(R.id.attachment_icon);