Bug 1399217 - Disable wasm disassembly for non-binary source. r=jlast

MozReview-Commit-ID: KEyyOjyKXPF

devtools/client/sourceeditor/editor.js

@@ -551,7 +551,7 @@ Editor.prototype = {
   setText: function (value) {
     let cm = editors.get(this);
 
-    if (typeof value !== "string") {  // wasm?
+    if (typeof value !== "string" && "binary" in value) {  // wasm?
       // binary does not survive as Uint8Array, converting from string
       let binary = value.binary;
       let data = new Uint8Array(binary.length);