From 3beacad57255fd27195e06f27f035ead5acb3db5 Mon Sep 17 00:00:00 2001
From: Howard Wang <sunbird.work@gmail.com>
Date: Thu, 23 Jul 2026 23:09:40 +0800
Subject: [PATCH] fix: work around broken WebAssembly streaming compile in
 Android WebView

Some Android System WebView builds throw on WebAssembly.compileStreaming /
instantiateStreaming even when the .wasm is fetched correctly (200
application/wasm). This breaks sites that load a wasm video decoder for 4K
playback, while the same URL plays fine in Chrome.

Inject a small shim (assets/wasm-streaming-shim.js) in onPageStarted, before
custom.js, that tries native streaming first and only falls back to
fetch -> arrayBuffer -> compile on failure. Healthy engines keep the fast
path; affected ones auto-recover.
---
 app/src/main/assets/wasm-streaming-shim.js    | 33 +++++++++++++++++++
 .../java/com/app/pakeplus/MainActivity.kt     |  3 ++
 2 files changed, 36 insertions(+)
 create mode 100644 app/src/main/assets/wasm-streaming-shim.js

diff --git a/app/src/main/assets/wasm-streaming-shim.js b/app/src/main/assets/wasm-streaming-shim.js
new file mode 100644
index 0000000000..64e6906454
--- /dev/null
+++ b/app/src/main/assets/wasm-streaming-shim.js
@@ -0,0 +1,33 @@
+// Fix WebAssembly streaming compilation on Android System WebView.
+// On some devices WebView's compileStreaming/instantiateStreaming throws
+// even when the .wasm is fetched correctly (200 application/wasm), which
+// breaks sites that load a wasm video decoder for 4K playback.
+// Strategy: try native streaming first (fast path on healthy engines);
+// only on failure, fall back to fetch -> arrayBuffer -> compile.
+(function () {
+    if (window.__wasmStreamingPatched) return;
+    if (typeof WebAssembly === 'undefined') return;
+    var _cs = WebAssembly.compileStreaming;
+    var _is = WebAssembly.instantiateStreaming;
+    if (typeof _cs === 'function') {
+        WebAssembly.compileStreaming = async function (src) {
+            try {
+                return await _cs.call(WebAssembly, src);
+            } catch (e) {
+                var resp = await src;
+                return WebAssembly.compile(await resp.arrayBuffer());
+            }
+        };
+    }
+    if (typeof _is === 'function') {
+        WebAssembly.instantiateStreaming = async function (src, imports) {
+            try {
+                return await _is.call(WebAssembly, src, imports);
+            } catch (e) {
+                var resp = await src;
+                return WebAssembly.instantiate(await resp.arrayBuffer(), imports);
+            }
+        };
+    }
+    window.__wasmStreamingPatched = true;
+})();
diff --git a/app/src/main/java/com/app/pakeplus/MainActivity.kt b/app/src/main/java/com/app/pakeplus/MainActivity.kt
index abbcaa1d6c..fddd6cc95c 100644
--- a/app/src/main/java/com/app/pakeplus/MainActivity.kt
+++ b/app/src/main/java/com/app/pakeplus/MainActivity.kt
@@ -1056,6 +1056,9 @@ class MainActivity : AppCompatActivity() {
                 val openDebug = """var vConsole = new window.VConsole()"""
                 view?.evaluateJavascript(vConsole + openDebug, null)
             }
+            // inject WebAssembly streaming shim before any page script and before custom.js
+            val wasmShim = assets.open("wasm-streaming-shim.js").bufferedReader().use { it.readText() }
+            view?.evaluateJavascript(wasmShim, null)
             // inject js
             val injectJs = assets.open("custom.js").bufferedReader().use { it.readText() }
             view?.evaluateJavascript(injectJs, null)