From 4c62fe8b124b27d44fc7485b4be5a6f4fc94b8ee Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Sun, 4 Jun 2023 11:33:18 +0300
Subject: [PATCH] Don't add reply sender to mentions array manually

Discord already adds it to the native mentions array
---
 backfill.go       |  4 ++--
 portal.go         | 20 ++++++++++----------
 portal_convert.go |  5 +----
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/backfill.go b/backfill.go
index c218646..4422163 100644
--- a/backfill.go
+++ b/backfill.go
@@ -217,8 +217,8 @@ func (portal *Portal) convertMessageBatch(log zerolog.Logger, source *User, mess
 		puppet := portal.bridge.GetPuppetByID(msg.Author.ID)
 		puppet.UpdateInfo(source, msg.Author, msg.WebhookID)
 		intent := puppet.IntentFor(portal)
-		replyTo, replySenderMXID := portal.getReplyTarget(source, "", msg.MessageReference, msg.Embeds, true)
-		mentions := portal.convertDiscordMentions(msg, replySenderMXID, false)
+		replyTo := portal.getReplyTarget(source, "", msg.MessageReference, msg.Embeds, true)
+		mentions := portal.convertDiscordMentions(msg, false)
 
 		ts, _ := discordgo.SnowflakeTimestamp(msg.ID)
 		log := log.With().
diff --git a/portal.go b/portal.go
index b4f2005..4bd1ab4 100644
--- a/portal.go
+++ b/portal.go
@@ -636,8 +636,8 @@ func (portal *Portal) handleDiscordMessageCreate(user *User, msg *discordgo.Mess
 			lastThreadEvent = lastInThread.MXID
 		}
 	}
-	replyTo, replySenderMXID := portal.getReplyTarget(user, discordThreadID, msg.MessageReference, msg.Embeds, false)
-	mentions := portal.convertDiscordMentions(msg, replySenderMXID, true)
+	replyTo := portal.getReplyTarget(user, discordThreadID, msg.MessageReference, msg.Embeds, false)
+	mentions := portal.convertDiscordMentions(msg, true)
 
 	ts, _ := discordgo.SnowflakeTimestamp(msg.ID)
 	parts := portal.convertDiscordMessage(ctx, puppet, intent, msg)
@@ -688,7 +688,7 @@ func isReplyEmbed(embed *discordgo.MessageEmbed) bool {
 	return hackyReplyPattern.MatchString(embed.Description)
 }
 
-func (portal *Portal) getReplyTarget(source *User, threadID string, ref *discordgo.MessageReference, embeds []*discordgo.MessageEmbed, allowNonExistent bool) (*event.InReplyTo, id.UserID) {
+func (portal *Portal) getReplyTarget(source *User, threadID string, ref *discordgo.MessageReference, embeds []*discordgo.MessageEmbed, allowNonExistent bool) *event.InReplyTo {
 	if ref == nil && len(embeds) > 0 {
 		match := hackyReplyPattern.FindStringSubmatch(embeds[0].Description)
 		if match != nil && match[1] == portal.GuildID && (match[2] == portal.Key.ChannelID || match[2] == threadID) {
@@ -700,7 +700,7 @@ func (portal *Portal) getReplyTarget(source *User, threadID string, ref *discord
 		}
 	}
 	if ref == nil {
-		return nil, ""
+		return nil
 	}
 	isHungry := portal.bridge.Config.Homeserver.Software == bridgeconfig.SoftwareHungry
 	if !isHungry {
@@ -713,25 +713,25 @@ func (portal *Portal) getReplyTarget(source *User, threadID string, ref *discord
 	if ref.ChannelID != portal.Key.ChannelID && ref.ChannelID != threadID && crossRoomReplies {
 		targetPortal = portal.bridge.GetExistingPortalByID(database.PortalKey{ChannelID: ref.ChannelID, Receiver: source.DiscordID})
 		if targetPortal == nil {
-			return nil, ""
+			return nil
 		}
 	}
 	replyToMsg := portal.bridge.DB.Message.GetByDiscordID(targetPortal.Key, ref.MessageID)
 	if len(replyToMsg) > 0 {
 		if !crossRoomReplies {
-			return &event.InReplyTo{EventID: replyToMsg[0].MXID}, replyToMsg[0].SenderMXID
+			return &event.InReplyTo{EventID: replyToMsg[0].MXID}
 		}
 		return &event.InReplyTo{
 			EventID:        replyToMsg[0].MXID,
 			UnstableRoomID: targetPortal.MXID,
-		}, replyToMsg[0].SenderMXID
+		}
 	} else if allowNonExistent {
 		return &event.InReplyTo{
 			EventID:        targetPortal.deterministicEventID(ref.MessageID, ""),
 			UnstableRoomID: targetPortal.MXID,
-		}, ""
+		}
 	}
-	return nil, ""
+	return nil
 }
 
 const JoinThreadReaction = "join thread"
@@ -902,7 +902,7 @@ func (portal *Portal) handleDiscordMessageUpdate(user *User, msg *discordgo.Mess
 	}
 	puppet.addWebhookMeta(converted, msg)
 	puppet.addMemberMeta(converted, msg)
-	converted.Content.Mentions = portal.convertDiscordMentions(msg, "", false)
+	converted.Content.Mentions = portal.convertDiscordMentions(msg, false)
 	converted.Content.SetEdit(existing[0].MXID)
 	// Never actually mention new users of edits, only include mentions inside m.new_content
 	converted.Content.Mentions = &event.Mentions{}
diff --git a/portal_convert.go b/portal_convert.go
index c56ba7e..b11c65b 100644
--- a/portal_convert.go
+++ b/portal_convert.go
@@ -621,7 +621,7 @@ func isPlainGifMessage(msg *discordgo.Message) bool {
 			(msg.Embeds[0].Type == discordgo.EmbedTypeImage && msg.Embeds[0].Image == nil && msg.Embeds[0].Thumbnail != nil))
 }
 
-func (portal *Portal) convertDiscordMentions(msg *discordgo.Message, replySender id.UserID, syncGhosts bool) *event.Mentions {
+func (portal *Portal) convertDiscordMentions(msg *discordgo.Message, syncGhosts bool) *event.Mentions {
 	var matrixMentions event.Mentions
 	for _, mention := range msg.Mentions {
 		puppet := portal.bridge.GetPuppetByID(mention.ID)
@@ -635,9 +635,6 @@ func (portal *Portal) convertDiscordMentions(msg *discordgo.Message, replySender
 			matrixMentions.UserIDs = append(matrixMentions.UserIDs, puppet.MXID)
 		}
 	}
-	if replySender != "" {
-		matrixMentions.UserIDs = append(matrixMentions.UserIDs, replySender)
-	}
 	slices.Sort(matrixMentions.UserIDs)
 	matrixMentions.UserIDs = slices.Compact(matrixMentions.UserIDs)
 	if msg.MentionEveryone {