From d88894c36590d3b71896f06334f8e9ef39a25fa4 Mon Sep 17 00:00:00 2001
From: Brendan Hansknecht <brendan.hansknecht@gmail.com>
Date: Mon, 13 Mar 2023 14:08:11 -0700
Subject: [PATCH] avoid zero sized allocation in false

---
 .../cli/false-interpreter/platform/src/lib.rs | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/examples/cli/false-interpreter/platform/src/lib.rs b/examples/cli/false-interpreter/platform/src/lib.rs
index 897eaea4d2..05f840634b 100644
--- a/examples/cli/false-interpreter/platform/src/lib.rs
+++ b/examples/cli/false-interpreter/platform/src/lib.rs
@@ -134,18 +134,26 @@ pub extern "C" fn rust_main() -> i32 {
 
 unsafe fn call_the_closure(closure_data_ptr: *const u8) -> i64 {
     let size = size_Fx_result() as usize;
-    let layout = Layout::array::<u8>(size).unwrap();
-    let buffer = std::alloc::alloc(layout) as *mut u8;
+    if size == 0 {
+        call_Fx(
+            // This flags pointer will never get dereferenced
+            MaybeUninit::uninit().as_ptr(),
+            closure_data_ptr as *const u8,
+            std::ptr::null_mut(),
+        );
+    } else {
+        let layout = Layout::array::<u8>(size).unwrap();
+        let buffer = std::alloc::alloc(layout) as *mut u8;
 
-    call_Fx(
-        // This flags pointer will never get dereferenced
-        MaybeUninit::uninit().as_ptr(),
-        closure_data_ptr as *const u8,
-        buffer as *mut u8,
-    );
-
-    std::alloc::dealloc(buffer, layout);
+        call_Fx(
+            // This flags pointer will never get dereferenced
+            MaybeUninit::uninit().as_ptr(),
+            closure_data_ptr as *const u8,
+            buffer as *mut u8,
+        );
 
+        std::alloc::dealloc(buffer, layout);
+    }
     0
 }