From 9c1ce702bb2ea50d7055028ffb30d3995220e8e6 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 24 May 2019 09:55:16 +0200
Subject: [PATCH] Display channel posts in discussion groups.

---
 .../history/history_item_components.cpp         | 17 ++++++++++++++---
 .../SourceFiles/history/history_message.cpp     | 10 +++++++++-
 Telegram/SourceFiles/history/history_message.h  |  2 +-
 .../history/view/history_view_element.cpp       | 15 ++++++++++-----
 .../history/view/history_view_message.cpp       | 14 +++++---------
 5 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/Telegram/SourceFiles/history/history_item_components.cpp b/Telegram/SourceFiles/history/history_item_components.cpp
index 902a52e7a..01fc882ad 100644
--- a/Telegram/SourceFiles/history/history_item_components.cpp
+++ b/Telegram/SourceFiles/history/history_item_components.cpp
@@ -233,9 +233,20 @@ bool HistoryMessageReply::isNameUpdated() const {
 
 void HistoryMessageReply::updateName() const {
 	if (replyToMsg) {
-		QString name = (replyToVia && replyToMsg->author()->isUser())
-			? replyToMsg->author()->asUser()->firstName
-			: App::peerName(replyToMsg->author());
+		const auto from = [&] {
+			if (const auto message = replyToMsg->toHistoryMessage()) {
+				if (const auto from = message->displayFrom()) {
+					return from;
+				}
+			}
+			return replyToMsg->author().get();
+		}();
+		const auto name = [&] {
+			if (replyToVia && from->isUser()) {
+				return from->asUser()->firstName;
+			}
+			return App::peerName(from);
+		}();
 		replyToName.setText(st::fwdTextStyle, name, Ui::NameTextOptions());
 		replyToVersion = replyToMsg->author()->nameVersion;
 		bool hasPreview = replyToMsg->media() ? replyToMsg->media()->hasReplyPreview() : false;
diff --git a/Telegram/SourceFiles/history/history_message.cpp b/Telegram/SourceFiles/history/history_message.cpp
index 35ee9620b..937be612d 100644
--- a/Telegram/SourceFiles/history/history_message.cpp
+++ b/Telegram/SourceFiles/history/history_message.cpp
@@ -553,8 +553,16 @@ int HistoryMessage::viewsCount() const {
 	return HistoryItem::viewsCount();
 }
 
+bool HistoryMessage::displayForwardedAsOriginal() const {
+	if (const auto forwarded = Get<HistoryMessageForwarded>()) {
+		const auto peer = history()->peer;
+		return peer->isSelf() || (peer->isMegagroup() && (peer == from()));
+	}
+	return false;
+}
+
 PeerData *HistoryMessage::displayFrom() const {
-	return history()->peer->isSelf()
+	return displayForwardedAsOriginal()
 		? senderOriginal()
 		: author().get();
 }
diff --git a/Telegram/SourceFiles/history/history_message.h b/Telegram/SourceFiles/history/history_message.h
index 80c34e68e..cf0703015 100644
--- a/Telegram/SourceFiles/history/history_message.h
+++ b/Telegram/SourceFiles/history/history_message.h
@@ -131,6 +131,7 @@ public:
 	MsgId dependencyMsgId() const override {
 		return replyToId();
 	}
+	bool displayForwardedAsOriginal() const;
 
 	HistoryMessage *toHistoryMessage() override { // dynamic_cast optimize
 		return this;
@@ -170,7 +171,6 @@ private:
 		const MTPDmessageFwdHeader &data);
 
 	void updateAdminBadgeState();
-	ClickHandlerPtr fastReplyLink() const;
 
 	QString _timeText;
 	int _timeWidth = 0;
diff --git a/Telegram/SourceFiles/history/view/history_view_element.cpp b/Telegram/SourceFiles/history/view/history_view_element.cpp
index df7fcc47a..5193a590c 100644
--- a/Telegram/SourceFiles/history/view/history_view_element.cpp
+++ b/Telegram/SourceFiles/history/view/history_view_element.cpp
@@ -358,15 +358,20 @@ void Element::refreshDataId() {
 }
 
 bool Element::computeIsAttachToPrevious(not_null<Element*> previous) {
+	const auto mayBeAttached = [](not_null<HistoryItem*> item) {
+		return !item->serviceMsg()
+			&& !item->isEmpty()
+			&& !item->isPost()
+			&& (item->from() != item->history()->peer
+				|| !item->from()->isChannel());
+	};
 	const auto item = data();
 	if (!Has<DateBadge>() && !Has<UnreadBar>()) {
 		const auto prev = previous->data();
-		const auto possible = !item->serviceMsg() && !prev->serviceMsg()
-			&& !item->isEmpty() && !prev->isEmpty()
-			&& (std::abs(prev->date() - item->date())
+		const auto possible = (std::abs(prev->date() - item->date())
 				< kAttachMessageToPreviousSecondsDelta)
-			&& (/*_context == Context::Feed // #feed
-				|| */(!item->isPost() && !prev->isPost()));
+			&& mayBeAttached(item)
+			&& mayBeAttached(prev);
 		if (possible) {
 			if (item->history()->peer->isSelf()) {
 				return IsAttachedToPreviousInSavedMessages(prev, item);
diff --git a/Telegram/SourceFiles/history/view/history_view_message.cpp b/Telegram/SourceFiles/history/view/history_view_message.cpp
index ac2e15177..91f53881c 100644
--- a/Telegram/SourceFiles/history/view/history_view_message.cpp
+++ b/Telegram/SourceFiles/history/view/history_view_message.cpp
@@ -1335,10 +1335,9 @@ bool Message::displayFromName() const {
 
 bool Message::displayForwardedFrom() const {
 	const auto item = message();
-	if (const auto forwarded = item->Get<HistoryMessageForwarded>()) {
-		if (item->history()->peer->isSelf()) {
-			return false;
-		}
+	if (item->displayForwardedAsOriginal()) {
+		return false;
+	} else if (const auto forwarded = item->Get<HistoryMessageForwarded>()) {
 		const auto media = this->media();
 		return item->Has<HistoryMessageVia>()
 			|| !media
@@ -1419,11 +1418,8 @@ bool Message::displayFastShare() const {
 
 bool Message::displayGoToOriginal() const {
 	const auto item = message();
-	const auto peer = item->history()->peer;
-	if (peer->isSelf()) {
-		if (const auto forwarded = item->Get<HistoryMessageForwarded>()) {
-			return forwarded->savedFromPeer && forwarded->savedFromMsgId;
-		}
+	if (const auto forwarded = item->Get<HistoryMessageForwarded>()) {
+		return forwarded->savedFromPeer && forwarded->savedFromMsgId;
 	}
 	return false;
 }