Probably fix #703

mastodon/src/main/java/org/joinmastodon/android/model/Hashtag.java

@@ -30,4 +30,19 @@ public class Hashtag extends BaseModel implements DisplayItemsParent{
 	public String getID(){
 		return name;
 	}
+
+	@Override
+	public boolean equals(Object o){
+		if(this==o) return true;
+		if(o==null || getClass()!=o.getClass()) return false;
+
+		Hashtag hashtag=(Hashtag) o;
+
+		return name.equals(hashtag.name);
+	}
+
+	@Override
+	public int hashCode(){
+		return name.hashCode();
+	}
 }

mastodon/src/main/java/org/joinmastodon/android/model/Mention.java

@@ -20,4 +20,22 @@ public class Mention extends BaseModel{
 				", url='"+url+'\''+
 				'}';
 	}
+
+	@Override
+	public boolean equals(Object o){
+		if(this==o) return true;
+		if(o==null || getClass()!=o.getClass()) return false;
+
+		Mention mention=(Mention) o;
+
+		if(!id.equals(mention.id)) return false;
+		return url.equals(mention.url);
+	}
+
+	@Override
+	public int hashCode(){
+		int result=id.hashCode();
+		result=31*result+url.hashCode();
+		return result;
+	}
 }