Improve handling of attachments with captions.

SignalServiceKit/src/Messages/Interactions/TSMessage.m

@@ -3,6 +3,7 @@
 //
 
 #import "TSMessage.h"
+#import "AppContext.h"
 #import "NSDate+OWS.h"
 #import "NSString+SSK.h"
 #import "TSAttachment.h"
@@ -241,18 +242,37 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
 
 - (NSString *)previewTextWithTransaction:(YapDatabaseReadTransaction *)transaction
 {
-    if (self.body.length > 0) {
-        // Use the message text/caption, if any.
-        return self.body;
-    } else if ([self hasAttachments]) {
+    NSString *_Nullable attachmentDescription = nil;
+    if ([self hasAttachments]) {
         NSString *attachmentId = self.attachmentIds[0];
         TSAttachment *attachment = [TSAttachment fetchObjectWithUniqueID:attachmentId transaction:transaction];
         if (attachment) {
-            return attachment.description;
+            attachmentDescription = attachment.description;
         } else {
-            return NSLocalizedString(@"UNKNOWN_ATTACHMENT_LABEL", @"In Inbox view, last message label for thread with corrupted attachment.");
+            attachmentDescription = NSLocalizedString(@"UNKNOWN_ATTACHMENT_LABEL",
+                @"In Inbox view, last message label for thread with corrupted attachment.");
+        }
+    }
+
+    NSString *_Nullable bodyDescription = nil;
+    if (self.body.length > 0) {
+        // TODO: Filter this text using something like DisplayableText.
+        bodyDescription = self.body;
+    }
+
+    if (attachmentDescription.length > 0 && bodyDescription.length > 0) {
+        // Attachment with caption.
+        if ([CurrentAppContext() isRTL]) {
+            return [[bodyDescription stringByAppendingString:@": "] stringByAppendingString:attachmentDescription];
+        } else {
+            return [[attachmentDescription stringByAppendingString:@": "] stringByAppendingString:bodyDescription];
         }
+    } else if (bodyDescription.length > 0) {
+        return bodyDescription;
+    } else if (attachmentDescription.length > 0) {
+        return attachmentDescription;
     } else {
+        OWSFail(@"%@ message has neither body nor attachment.", self.logTag);
         // TODO: We should do better here.
         return @"";
     }
@@ -273,6 +293,7 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
             return NSLocalizedString(@"UNKNOWN_ATTACHMENT_LABEL", @"In Inbox view, last message label for thread with corrupted attachment.");
         }
     } else {
+        OWSFail(@"%@ message has neither body nor attachment.", self.logTag);
         // TODO: We should do better here.
         return @"";
     }

SignalServiceKit/src/Messages/OWSMessageSender.m

@@ -1153,7 +1153,11 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
     [self handleMessageSentLocally:outgoingMessage];
 
     if (!(outgoingMessage.body || outgoingMessage.hasAttachments)) {
-        DDLogDebug(@"%@ Refusing to make incoming copy of non-standard message sent to self: %@",
+        // We only want to "clone" text and attachment messages.
+        //
+        // This method shouldn't be called for sync messages, so this
+        // probably represents a bug.
+        OWSFail(@"%@ Refusing to make incoming copy of non-standard message sent to self: %@",
             self.logTag,
             outgoingMessage);
         return;