From 32ee93ef7399529cc9a97557ded0fb497f2f3670 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 20 Jan 2020 15:43:14 +0100
Subject: [PATCH] fix(runtime-c-api) `wasmer_instance_context_data_set` does
 nothing if `instance` is null.

---
 lib/runtime-c-api/src/instance.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/runtime-c-api/src/instance.rs b/lib/runtime-c-api/src/instance.rs
index cf97452e3..e203093a8 100644
--- a/lib/runtime-c-api/src/instance.rs
+++ b/lib/runtime-c-api/src/instance.rs
@@ -428,8 +428,13 @@ pub extern "C" fn wasmer_instance_context_data_set(
     instance: *mut wasmer_instance_t,
     data_ptr: *mut c_void,
 ) {
-    let instance_ref = unsafe { &mut *(instance as *mut Instance) };
-    instance_ref.context_mut().data = data_ptr;
+    if instance.is_null() {
+        return;
+    }
+
+    let instance = unsafe { &mut *(instance as *mut Instance) };
+
+    instance.context_mut().data = data_ptr;
 }
 
 /// Gets the memory within the context at the index `memory_idx`.