From 3d1c4a8589ed31728da29c2a8830f4acd96e94eb Mon Sep 17 00:00:00 2001
From: glx22 <glx@openttd.org>
Date: Thu, 6 Jul 2023 18:18:03 +0200
Subject: [PATCH] Codechange: [Emscripten] Improve syncfs synchronisation on
 exit/abort

---
 os/emscripten/pre.js | 22 ++++++++++++----------
 src/openttd.cpp      |  1 -
 src/video/sdl2_v.cpp |  1 -
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/os/emscripten/pre.js b/os/emscripten/pre.js
index c242e13fd0..68e76678aa 100644
--- a/os/emscripten/pre.js
+++ b/os/emscripten/pre.js
@@ -52,24 +52,26 @@ Module.preRun.push(function() {
     });
 
     window.openttd_syncfs_shown_warning = false;
-    window.openttd_syncfs = function() {
+    window.openttd_syncfs = function(callback) {
         /* Copy the virtual FS to the persistent storage. */
-        FS.syncfs(false, function (err) { });
+        FS.syncfs(false, function (err) {
+            /* On first time, warn the user about the volatile behaviour of
+             * persistent storage. */
+            if (!window.openttd_syncfs_shown_warning) {
+                window.openttd_syncfs_shown_warning = true;
+                Module.onWarningFs();
+            }
 
-        /* On first time, warn the user about the volatile behaviour of
-         * persistent storage. */
-        if (!window.openttd_syncfs_shown_warning) {
-            window.openttd_syncfs_shown_warning = true;
-            Module.onWarningFs();
-        }
+            if (callback) callback();
+        });
     }
 
     window.openttd_exit = function() {
-        Module.onExit();
+        window.openttd_syncfs(Module.onExit);
     }
 
     window.openttd_abort = function() {
-        Module.onAbort();
+        window.openttd_syncfs(Module.onAbort);
     }
 
     window.openttd_server_list = function() {
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 5356f38fbd..6fb3b4a34f 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -118,7 +118,6 @@ void UserErrorI(const std::string &str)
 	/* In effect, the game ends here. As emscripten_set_main_loop() caused
 	 * the stack to be unwound, the code after MainLoop() in
 	 * openttd_main() is never executed. */
-	EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
 	EM_ASM(if (window["openttd_abort"]) openttd_abort());
 #endif
 
diff --git a/src/video/sdl2_v.cpp b/src/video/sdl2_v.cpp
index eb201f0774..1f18d143fd 100644
--- a/src/video/sdl2_v.cpp
+++ b/src/video/sdl2_v.cpp
@@ -615,7 +615,6 @@ void VideoDriver_SDL_Base::LoopOnce()
 		/* In effect, the game ends here. As emscripten_set_main_loop() caused
 		 * the stack to be unwound, the code after MainLoop() in
 		 * openttd_main() is never executed. */
-		EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
 		EM_ASM(if (window["openttd_exit"]) openttd_exit());
 #endif
 		return;