From d89990951ee2a8d90707f012cefba0e4067a3a7f Mon Sep 17 00:00:00 2001
From: Brandon Fish <brandon.j.fish@gmail.com>
Date: Fri, 16 Aug 2019 22:18:13 -0600
Subject: [PATCH] Convert panic to error when calling emscripten main

---
 lib/emscripten/src/lib.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/emscripten/src/lib.rs b/lib/emscripten/src/lib.rs
index c37e34d8e34..2f03dbb3b6e 100644
--- a/lib/emscripten/src/lib.rs
+++ b/lib/emscripten/src/lib.rs
@@ -16,7 +16,7 @@ use std::collections::HashMap;
 use std::path::PathBuf;
 use std::{f64, ffi::c_void};
 use wasmer_runtime_core::{
-    error::CallResult,
+    error::{CallError, CallResult, ResolveError},
     export::Export,
     func,
     global::Global,
@@ -373,10 +373,11 @@ pub fn run_emscripten_instance(
             0 => {
                 instance.call(func_name, &[])?;
             }
-            _ => panic!(
-                "The emscripten main function has received an incorrect number of params {}",
-                num_params
-            ),
+            _ => {
+                return Err(CallError::Resolve(ResolveError::ExportWrongType {
+                    name: "main".to_string(),
+                }))
+            }
         };
     }