Make long text attachments contain the entire message.

Instead of just containing the 'overflow', long text attachments now
contain the entire body in full.

src/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -1968,20 +1968,20 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
   private Pair<String, Optional<Slide>> getSplitMessage(String rawText, int maxPrimaryMessageSize) {
     String          bodyText  = rawText;
-    Optional<Slide> extraText = Optional.absent();
+    Optional<Slide> textSlide = Optional.absent();
 
     if (bodyText.length() > maxPrimaryMessageSize) {
       bodyText = rawText.substring(0, maxPrimaryMessageSize);
 
-      byte[] extraData = rawText.substring(maxPrimaryMessageSize).getBytes();
+      byte[] textData  = rawText.getBytes();
-      Uri    textUri   = MemoryBlobProvider.getInstance().createUri(extraData);
+      Uri    textUri   = MemoryBlobProvider.getInstance().createUri(textData);
       String timestamp = new SimpleDateFormat("yyyy-MM-dd-HHmmss", Locale.US).format(new Date());
       String filename  = String.format("signal-%s.txt", timestamp);
 
-      extraText = Optional.of(new TextSlide(this, textUri, filename, extraData.length));
+      textSlide = Optional.of(new TextSlide(this, textUri, filename, textData.length));
     }
 
-    return new Pair<>(bodyText, extraText);
+    return new Pair<>(bodyText, textSlide);
   }
 
   private MediaConstraints getCurrentMediaConstraints() {

src/org/thoughtcrime/securesms/conversation/ConversationFragment.java

@@ -564,8 +564,8 @@ public class ConversationFragment extends Fragment
 
         if (mediaMessage.getSlideDeck().getTextSlide() != null && mediaMessage.getSlideDeck().getTextSlide().getUri() != null) {
           try (InputStream stream = PartAuthority.getAttachmentStream(requireContext(), mediaMessage.getSlideDeck().getTextSlide().getUri())) {
-            String extraText = Util.readFullyAsString(stream);
+            String fullBody = Util.readFullyAsString(stream);
-            composeIntent.putExtra(Intent.EXTRA_TEXT, message.getDisplayBody().toString() + extraText);
+            composeIntent.putExtra(Intent.EXTRA_TEXT, fullBody);
           } catch (IOException e) {
             Log.w(TAG, "Failed to read long message text when forwarding.");
           }

src/org/thoughtcrime/securesms/longmessage/LongMessage.java

@@ -1,5 +1,7 @@
 package org.thoughtcrime.securesms.longmessage;
 
+import android.text.TextUtils;
+
 import org.thoughtcrime.securesms.database.model.MessageRecord;
 
 /**
@@ -9,11 +11,11 @@ import org.thoughtcrime.securesms.database.model.MessageRecord;
 class LongMessage {
 
   private final MessageRecord messageRecord;
-  private final String        extraBody;
+  private final String        fullBody;
 
-  LongMessage(MessageRecord messageRecord, String extraBody) {
+  LongMessage(MessageRecord messageRecord, String fullBody) {
     this.messageRecord = messageRecord;
-    this.extraBody     = extraBody;
+    this.fullBody      = fullBody;
   }
 
   MessageRecord getMessageRecord() {
@@ -21,6 +23,6 @@ class LongMessage {
   }
 
   String getFullBody() {
-    return messageRecord.getBody() + extraBody;
+    return !TextUtils.isEmpty(fullBody) ? fullBody : messageRecord.getBody();
   }
 }