Fix viewing attachment with alternative MIME type

k9mail/src/main/java/com/fsck/k9/mailstore/AttachmentViewInfo.java

@@ -12,6 +12,14 @@ public class AttachmentViewInfo {
     public final String mimeType;
     public final String displayName;
     public final long size;
+
+    /**
+     * A content provider URI that can be used to retrieve the decoded attachment.
+     * <p/>
+     * Note: All content providers must support an alternative MIME type appended as last URI segment.
+     *
+     * @see com.fsck.k9.ui.messageview.AttachmentController#getAttachmentUriForMimeType(AttachmentViewInfo, String)
+     */
     public final Uri uri;
     public final boolean firstClassAttachment;
     public final Part part;

k9mail/src/main/java/com/fsck/k9/provider/AttachmentProvider.java

@@ -18,6 +18,7 @@ import com.fsck.k9.Account;
 import com.fsck.k9.K9;
 import com.fsck.k9.Preferences;
 import com.fsck.k9.mail.MessagingException;
+import com.fsck.k9.mail.internet.MimeUtility;
 import com.fsck.k9.mailstore.LocalStore;
 import com.fsck.k9.mailstore.LocalStore.AttachmentInfo;
 import org.openintents.openpgp.util.ParcelFileDescriptorUtil;
@@ -25,17 +26,10 @@ import org.openintents.openpgp.util.ParcelFileDescriptorUtil;
 
 /**
  * A simple ContentProvider that allows file access to attachments.
- * <p>
- * Warning! We make heavy assumptions about the Uris used by the {@link LocalStore} for an
- * {@link Account} here.
- * </p>
  */
 public class AttachmentProvider extends ContentProvider {
     public static final Uri CONTENT_URI = Uri.parse("content://com.fsck.k9.attachmentprovider");
 
-    private static final String FORMAT_RAW = "RAW";
-    private static final String FORMAT_VIEW = "VIEW";
-
     private static final String[] DEFAULT_PROJECTION = new String[] {
             AttachmentProviderColumns._ID,
             AttachmentProviderColumns.DATA,
@@ -53,7 +47,6 @@ public class AttachmentProvider extends ContentProvider {
         return CONTENT_URI.buildUpon()
                 .appendPath(accountUuid)
                 .appendPath(Long.toString(id))
-                .appendPath(FORMAT_RAW)
                 .build();
     }
 
@@ -67,10 +60,9 @@ public class AttachmentProvider extends ContentProvider {
         List<String> segments = uri.getPathSegments();
         String accountUuid = segments.get(0);
         String id = segments.get(1);
-        String format = segments.get(2);
+        String mimeType = (segments.size() < 3) ? null : segments.get(2);
-        String mimeType = (segments.size() < 4) ? null : segments.get(3);
 
-        return getType(accountUuid, id, format, mimeType);
+        return getType(accountUuid, id, mimeType);
     }
 
     @Override
@@ -140,7 +132,7 @@ public class AttachmentProvider extends ContentProvider {
         return null;
     }
 
-    private String getType(String accountUuid, String id, String format, String mimeType) {
+    private String getType(String accountUuid, String id, String mimeType) {
         String type;
         final Account account = Preferences.getPreferences(getContext()).getAccount(accountUuid);
 
@@ -148,14 +140,14 @@ public class AttachmentProvider extends ContentProvider {
             final LocalStore localStore = LocalStore.getInstance(account, getContext());
 
             AttachmentInfo attachmentInfo = localStore.getAttachmentInfo(id);
-            if (FORMAT_VIEW.equals(format) && mimeType != null) {
+            if (mimeType != null) {
                 type = mimeType;
             } else {
                 type = attachmentInfo.type;
             }
         } catch (MessagingException e) {
             Log.e(K9.LOG_TAG, "Unable to retrieve LocalStore for " + account, e);
-            type = null;
+            type = MimeUtility.DEFAULT_ATTACHMENT_MIME_TYPE;
         }
 
         return type;

k9mail/src/main/java/com/fsck/k9/ui/messageview/AttachmentController.java

@@ -158,14 +158,26 @@ public class AttachmentController {
     }
 
     private Intent createViewIntentForAttachmentProviderUri(String mimeType) {
+        Uri uri = getAttachmentUriForMimeType(attachment, mimeType);
+
         Intent intent = new Intent(Intent.ACTION_VIEW);
-        intent.setDataAndType(attachment.uri, mimeType);
+        intent.setDataAndType(uri, mimeType);
         intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
         addUiIntentFlags(intent);
 
         return intent;
     }
 
+    private Uri getAttachmentUriForMimeType(AttachmentViewInfo attachment, String mimeType) {
+        if (attachment.mimeType.equals(mimeType)) {
+            return attachment.uri;
+        }
+
+        return attachment.uri.buildUpon()
+                .appendPath(mimeType)
+                .build();
+    }
+
     private Intent createViewIntentForFileUri(String mimeType, Uri uri) {
         Intent intent = new Intent(Intent.ACTION_VIEW);
         intent.setDataAndType(uri, mimeType);