From ff6365ec72842f4cf53120716dea86e8f5665796 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 14 Apr 2020 15:38:29 +0400
Subject: [PATCH] Fix crash in still downloaded ~DocumentData.

---
 Telegram/SourceFiles/data/data_document.cpp    | 1 +
 Telegram/SourceFiles/storage/file_download.cpp | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Telegram/SourceFiles/data/data_document.cpp b/Telegram/SourceFiles/data/data_document.cpp
index 75677b966..72c3e2552 100644
--- a/Telegram/SourceFiles/data/data_document.cpp
+++ b/Telegram/SourceFiles/data/data_document.cpp
@@ -749,6 +749,7 @@ void DocumentData::automaticLoadSettingsChanged() {
 }
 
 void DocumentData::finishLoad() {
+	// NB! _loader may be in ~FileLoader() already.
 	const auto guard = gsl::finally([&] {
 		destroyLoader();
 	});
diff --git a/Telegram/SourceFiles/storage/file_download.cpp b/Telegram/SourceFiles/storage/file_download.cpp
index 7a32d5670..75ad3fa36 100644
--- a/Telegram/SourceFiles/storage/file_download.cpp
+++ b/Telegram/SourceFiles/storage/file_download.cpp
@@ -43,7 +43,11 @@ FileLoader::FileLoader(
 	Expects(!_filename.isEmpty() || (_size <= Storage::kMaxFileInMemory));
 }
 
-FileLoader::~FileLoader() = default;
+FileLoader::~FileLoader() {
+	if (!_finished) {
+		cancel();
+	}
+}
 
 Main::Session &FileLoader::session() const {
 	return *_session;