Fix bug in thread building using status context

It cannot be assumed that an ancestor will exist
when building a thread using the status context
API. Use the current orphan as the starting point
if no ancestor exists.

client/client.go

@@ -114,16 +114,26 @@ func (c *Client) buildOrphans() error {
 			return err
 		}
 
-		top := statusContext.Ancestors[0]
+		var top Post;
 
-		for i := range statusContext.Ancestors[1:] {
-			post := statusContext.Ancestors[i+1]
-			c.postIdMap[post.Id] = &post
-			top.descendants = append(top.descendants, &post)
+		// When building a thread from the status context endpoint, 
+		// start from the greatest ancestor and add the other ancestors
+		// below it as descendants.
+		// Otherwise, use the orphan as the start. 
+		if len(statusContext.Ancestors) > 0 {
+			top = statusContext.Ancestors[0]
+
+			for i := range statusContext.Ancestors[1:] {
+				post := statusContext.Ancestors[i+1]
+				c.postIdMap[post.Id] = &post
+				top.descendants = append(top.descendants, &post)
+			}
+
+			top.descendants = append(top.descendants, c.postIdMap[postId])
+		} else {
+			top = *c.postIdMap[postId]
 		}
 
-		top.descendants = append(top.descendants, c.postIdMap[postId])
-
 		for i := range statusContext.Descendants {
 			post := statusContext.Descendants[i]
 			if post.Account.Id != c.account.Id {

main.go

@@ -43,7 +43,7 @@ func main() {
 		MinId:          *minId,
 		OnlyMedia:      *onlyMedia,
 		Pinned:         *pinned,
-		Tagged: *tagged,
+		Tagged:         *tagged,
 	}, client.ClientOptions{
 		Threaded:   *threaded,
 		Visibility: *visibility,