From e6c0f0f774c328f6c5b991040aed79f00859d3dd Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 9 Mar 2018 15:18:28 +0300
Subject: [PATCH] Up arrow always edits last available message.

Fixes #4480.
---
 Telegram/SourceFiles/history/history.cpp      | 19 +++++++++++++++----
 Telegram/SourceFiles/history/history.h        |  2 +-
 .../SourceFiles/history/history_widget.cpp    | 17 ++++++++++-------
 Telegram/SourceFiles/mainwidget.cpp           |  2 --
 4 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/Telegram/SourceFiles/history/history.cpp b/Telegram/SourceFiles/history/history.cpp
index 5489bc31f..2d12ca128 100644
--- a/Telegram/SourceFiles/history/history.cpp
+++ b/Telegram/SourceFiles/history/history.cpp
@@ -1223,9 +1223,6 @@ void History::clearSendAction(not_null<UserData*> from) {
 void History::mainViewRemoved(
 		not_null<HistoryBlock*> block,
 		not_null<HistoryView::Element*> view) {
-	if (lastSentMsg == view->data()) {
-		lastSentMsg = nullptr;
-	}
 	if (_joinedMessage == view->data()) {
 		_joinedMessage = nullptr;
 	}
@@ -2271,6 +2268,21 @@ MsgId History::msgIdForRead() const {
 		: result;
 }
 
+HistoryItem *History::lastSentMessage() const {
+	if (!loadedAtBottom()) {
+		return nullptr;
+	}
+	for (const auto &block : base::reversed(blocks)) {
+		for (const auto &message : base::reversed(block->messages)) {
+			const auto item = message->data();
+			if (IsServerMsgId(item->id) && item->out()) {
+				return item;
+			}
+		}
+	}
+	return nullptr;
+}
+
 void History::resizeToWidth(int newWidth) {
 	const auto resizeAllItems = (_width != newWidth);
 
@@ -2517,7 +2529,6 @@ void History::unloadBlocks() {
 void History::clearBlocks(bool leaveItems) {
 	_unreadBarView = nullptr;
 	_firstUnreadView = nullptr;
-	lastSentMsg = nullptr;
 	_joinedMessage = nullptr;
 
 	if (scrollTopItem) {
diff --git a/Telegram/SourceFiles/history/history.h b/Telegram/SourceFiles/history/history.h
index 2915f3ab0..92f87262a 100644
--- a/Telegram/SourceFiles/history/history.h
+++ b/Telegram/SourceFiles/history/history.h
@@ -242,6 +242,7 @@ public:
 	MsgId minMsgId() const;
 	MsgId maxMsgId() const;
 	MsgId msgIdForRead() const;
+	HistoryItem *lastSentMessage() const;
 
 	void resizeToWidth(int newWidth);
 	int height() const;
@@ -351,7 +352,6 @@ public:
 	std::deque<std::unique_ptr<HistoryBlock>> blocks;
 
 	not_null<PeerData*> peer;
-	HistoryItem *lastSentMsg = nullptr;
 
 	typedef QList<HistoryItem*> NotifyQueue;
 	NotifyQueue notifies;
diff --git a/Telegram/SourceFiles/history/history_widget.cpp b/Telegram/SourceFiles/history/history_widget.cpp
index 5af89a341..da6bf6fa0 100644
--- a/Telegram/SourceFiles/history/history_widget.cpp
+++ b/Telegram/SourceFiles/history/history_widget.cpp
@@ -5153,13 +5153,16 @@ void HistoryWidget::keyPressEvent(QKeyEvent *e) {
 		}
 	} else if (e->key() == Qt::Key_Up) {
 		if (!(e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier))) {
-			if (_history
-				&& _history->lastSentMsg
-				&& _history->lastSentMsg->allowsEdit(unixtime())) {
-				if (_field->isEmpty() && !_editMsgId && !_replyToId && _history->lastSentMsg) {
-					editMessage(_history->lastSentMsg);
-					return;
-				}
+			const auto item = _history
+				? _history->lastSentMessage()
+				: nullptr;
+			if (item
+				&& item->allowsEdit(unixtime())
+				&& _field->isEmpty()
+				&& !_editMsgId
+				&& !_replyToId) {
+				editMessage(item);
+				return;
 			}
 			_scroll->keyPressEvent(e);
 		} else if ((e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier)) == Qt::ControlModifier) {
diff --git a/Telegram/SourceFiles/mainwidget.cpp b/Telegram/SourceFiles/mainwidget.cpp
index f50a0268b..28acafb53 100644
--- a/Telegram/SourceFiles/mainwidget.cpp
+++ b/Telegram/SourceFiles/mainwidget.cpp
@@ -1345,8 +1345,6 @@ void MainWidget::sendMessage(const MessageToSend &message) {
 			history->sendRequestId);
 	}
 
-	history->lastSentMsg = lastMessage;
-
 	finishForwarding(history);
 }