From 234f0e4b033f1d8d38a639309ec33d65e0b016a3 Mon Sep 17 00:00:00 2001
From: daxpedda <daxpedda@gmail.com>
Date: Tue, 3 Oct 2023 12:21:45 +0200
Subject: [PATCH] Fix some calls to `free()` missing alignment

---
 CHANGELOG.md                         |  3 +++
 crates/cli-support/src/js/binding.rs | 10 +++++-----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96f7ff54b0f..1cfb25f59bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -132,6 +132,9 @@
 * Fix bug with function arguments coming from `macro_rules!`.
   [#3625](https://github.com/rustwasm/wasm-bindgen/pull/3625)
 
+* Fix some calls to `free()` missing alignment.
+  [#3639](https://github.com/rustwasm/wasm-bindgen/pull/3639)
+
 ### Removed
 
 * Removed `ReadableStreamByobReader::read_with_u8_array()` because it doesn't work with Wasm.
diff --git a/crates/cli-support/src/js/binding.rs b/crates/cli-support/src/js/binding.rs
index 1cd3e0f22da..c86927c6e8b 100644
--- a/crates/cli-support/src/js/binding.rs
+++ b/crates/cli-support/src/js/binding.rs
@@ -1056,7 +1056,7 @@ fn instruction(
             if *owned {
                 let free = js.cx.export_name_of(*free);
                 js.prelude(&format!(
-                    "if ({ptr} !== 0) {{ wasm.{}({ptr}, {len}); }}",
+                    "if ({ptr} !== 0) {{ wasm.{}({ptr}, {len}, 1); }}",
                     free,
                     ptr = ptr,
                     len = len,
@@ -1129,11 +1129,11 @@ fn instruction(
             let free = js.cx.export_name_of(*free);
             js.prelude(&format!("var v{} = {}({}, {}).slice();", i, f, ptr, len));
             js.prelude(&format!(
-                "wasm.{}({}, {} * {});",
+                "wasm.{}({}, {} * {size}, {size});",
                 free,
                 ptr,
                 len,
-                kind.size()
+                size = kind.size()
             ));
             js.push(format!("v{}", i))
         }
@@ -1148,11 +1148,11 @@ fn instruction(
             js.prelude(&format!("if ({} !== 0) {{", ptr));
             js.prelude(&format!("v{} = {}({}, {}).slice();", i, f, ptr, len));
             js.prelude(&format!(
-                "wasm.{}({}, {} * {});",
+                "wasm.{}({}, {} * {size}, {size});",
                 free,
                 ptr,
                 len,
-                kind.size()
+                size = kind.size()
             ));
             js.prelude("}");
             js.push(format!("v{}", i));