From f1b22ee02568779b1ea23c944936eadf9bd6f76c Mon Sep 17 00:00:00 2001
From: Christian Semmler <mail@csemmler.com>
Date: Thu, 3 Jul 2025 16:28:45 -0700
Subject: [PATCH] Allow Web port to be playable in Firefox Private (#513)

---
 ISLE/emscripten/emscripten.patch | 18 ++++++++++++++++++
 ISLE/emscripten/filesystem.cpp   | 17 +++++++++++++----
 ISLE/emscripten/filesystem.h     |  2 +-
 ISLE/isleapp.cpp                 | 11 +++++++----
 4 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/ISLE/emscripten/emscripten.patch b/ISLE/emscripten/emscripten.patch
index 899d72eb..0bc8222d 100644
--- a/ISLE/emscripten/emscripten.patch
+++ b/ISLE/emscripten/emscripten.patch
@@ -139,3 +139,21 @@ index e8c9f7e21..caf1971d2 100644
    },
 -
  });
+diff --git a/src/preamble.js b/src/preamble.js
+index 572694517..0d2f4421b 100644
+--- a/src/preamble.js
++++ b/src/preamble.js
+@@ -1062,3 +1062,13 @@ function getCompilerSetting(name) {
+ // dynamic linker as symbols are loaded.
+ var asyncifyStubs = {};
+ #endif
++
++(async () => {
++  try {
++    await navigator.storage.getDirectory();
++    Module["disableOpfs"] = false;
++  } catch (e) {
++    Module["disableOpfs"] = true;
++  }
++})();
++
diff --git a/ISLE/emscripten/filesystem.cpp b/ISLE/emscripten/filesystem.cpp
index 395242a1..50cd9012 100644
--- a/ISLE/emscripten/filesystem.cpp
+++ b/ISLE/emscripten/filesystem.cpp
@@ -6,6 +6,7 @@
 
 #include <SDL3/SDL_filesystem.h>
 #include <SDL3/SDL_log.h>
+#include <emscripten.h>
 #include <emscripten/wasmfs.h>
 
 static backend_t opfs = nullptr;
@@ -13,10 +14,16 @@ static backend_t fetchfs = nullptr;
 
 extern const char* g_files[46];
 
-void Emscripten_SetupConfig(const char* p_iniConfig)
+bool Emscripten_OPFSDisabled()
 {
-	if (!p_iniConfig || !*p_iniConfig) {
-		return;
+	return MAIN_THREAD_EM_ASM_INT({return !!Module["disableOpfs"]});
+}
+
+bool Emscripten_SetupConfig(const char* p_iniConfig)
+{
+	if (Emscripten_OPFSDisabled()) {
+		SDL_Log("OPFS is disabled; ignoring .ini path");
+		return false;
 	}
 
 	opfs = wasmfs_create_opfs_backend();
@@ -28,6 +35,8 @@ void Emscripten_SetupConfig(const char* p_iniConfig)
 		wasmfs_create_directory(iniConfig.GetData(), 0644, opfs);
 		*parse = '/';
 	}
+
+	return true;
 }
 
 void Emscripten_SetupFilesystem()
@@ -66,7 +75,7 @@ void Emscripten_SetupFilesystem()
 		registerFile(file);
 	}
 
-	if (GameState()->GetSavePath() && *GameState()->GetSavePath()) {
+	if (GameState()->GetSavePath() && *GameState()->GetSavePath() && !Emscripten_OPFSDisabled()) {
 		if (!opfs) {
 			opfs = wasmfs_create_opfs_backend();
 		}
diff --git a/ISLE/emscripten/filesystem.h b/ISLE/emscripten/filesystem.h
index 131df1c8..ad78a349 100644
--- a/ISLE/emscripten/filesystem.h
+++ b/ISLE/emscripten/filesystem.h
@@ -10,7 +10,7 @@ inline static const char* Emscripten_savePath = "/save";
 inline static const char* Emscripten_streamPath = "/";
 inline static const char* Emscripten_streamHost = ISLE_EMSCRIPTEN_HOST;
 
-void Emscripten_SetupConfig(const char* p_iniConfig);
+bool Emscripten_SetupConfig(const char* p_iniConfig);
 void Emscripten_SetupFilesystem();
 
 #endif // EMSCRIPTEN_FILESYSTEM_H
diff --git a/ISLE/isleapp.cpp b/ISLE/isleapp.cpp
index cfa3c50a..2e2066d8 100644
--- a/ISLE/isleapp.cpp
+++ b/ISLE/isleapp.cpp
@@ -778,6 +778,13 @@ bool IsleApp::LoadConfig()
 {
 	char* prefPath = SDL_GetPrefPath("isledecomp", "isle");
 	char* iniConfig;
+
+#ifdef __EMSCRIPTEN__
+	if (m_iniPath && !Emscripten_SetupConfig(m_iniPath)) {
+		m_iniPath = NULL;
+	}
+#endif
+
 	if (m_iniPath) {
 		iniConfig = new char[strlen(m_iniPath) + 1];
 		strcpy(iniConfig, m_iniPath);
@@ -793,10 +800,6 @@ bool IsleApp::LoadConfig()
 	}
 	SDL_Log("Reading configuration from \"%s\"", iniConfig);
 
-#ifdef __EMSCRIPTEN__
-	Emscripten_SetupConfig(iniConfig);
-#endif
-
 	dictionary* dict = iniparser_load(iniConfig);
 
 	// [library:config]