Fixed downloading messages

app/src/main/java/eu/faircode/email/DaoMessage.java

@@ -160,7 +160,7 @@ public interface DaoMessage {
 
     @Query("SELECT id FROM message" +
             " WHERE content" +
-            " AND preview IS NULL")
+            " AND (preview IS NULL OR preview = '')")
     List<Long> getMessageWithoutPreview();
 
     @Query("SELECT message.*" +
@@ -225,8 +225,8 @@ public interface DaoMessage {
     @Query("UPDATE message SET error = :error WHERE id = :id")
     int setMessageError(long id, String error);
 
-    @Query("UPDATE message SET content = NOT preview IS NULL, preview = :preview WHERE id = :id")
-    int setMessageContent(long id, String preview);
+    @Query("UPDATE message SET content = :content, preview = :preview WHERE id = :id")
+    int setMessageContent(long id, boolean content, String preview);
 
     @Query("UPDATE message SET headers = :headers WHERE id = :id")
     int setMessageHeaders(long id, String headers);

app/src/main/java/eu/faircode/email/FragmentOptions.java

@@ -134,12 +134,12 @@ public class FragmentOptions extends FragmentEx {
                                 try {
                                     Log.i(Helper.TAG, "Building preview id=" + id);
                                     String html = message.read(context);
-                                    String text = Jsoup.parse(html).text();
-                                    String preview = text.substring(0, Math.min(text.length(), 250));
-                                    db.message().setMessageContent(message.id, preview);
+                                    String text = (html == null ? null : Jsoup.parse(html).text());
+                                    String preview = (text == null ? null : text.substring(0, Math.min(text.length(), 250)));
+                                    db.message().setMessageContent(message.id, true, preview);
                                 } catch (IOException ex) {
                                     Log.e(Helper.TAG, ex + "\n" + Log.getStackTraceString(ex));
-                                    db.message().setMessageContent(message.id, null);
+                                    db.message().setMessageContent(message.id, false, null);
                                     if (!metered)
                                         EntityOperation.queue(db, message, EntityOperation.BODY);
                                 }

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -1435,10 +1435,10 @@ public class ServiceSynchronize extends LifecycleService {
 
         MessageHelper helper = new MessageHelper((MimeMessage) imessage);
         String html = helper.getHtml();
-        String text = (html == null ? "" : Jsoup.parse(html).text());
-        String preview = text.substring(0, Math.min(text.length(), PREVIEW_SIZE));
+        String text = (html == null ? null : Jsoup.parse(html).text());
+        String preview = (text == null ? null : text.substring(0, Math.min(text.length(), PREVIEW_SIZE)));
         message.write(this, html);
-        db.message().setMessageContent(message.id, preview);
+        db.message().setMessageContent(message.id, true, preview);
     }
 
     private void doAttachment(EntityFolder folder, EntityOperation op, IMAPFolder ifolder, EntityMessage message, JSONArray jargs, DB db) throws JSONException, MessagingException, IOException {
@@ -1896,10 +1896,10 @@ public class ServiceSynchronize extends LifecycleService {
         if (!message.content)
             if (!metered || (message.size != null && message.size < download)) {
                 String html = helper.getHtml();
-                String text = (html == null ? "" : Jsoup.parse(html).text());
-                String preview = text.substring(0, Math.min(text.length(), PREVIEW_SIZE));
+                String text = (html == null ? null : Jsoup.parse(html).text());
+                String preview = (text == null ? null : text.substring(0, Math.min(text.length(), PREVIEW_SIZE)));
                 message.write(context, html);
-                db.message().setMessageContent(message.id, preview);
+                db.message().setMessageContent(message.id, true, preview);
                 Log.i(Helper.TAG, folder.name + " downloaded message id=" + message.id + " size=" + message.size);
             }