added the code necessary to catch the error event from the spawn and send it to the callback

Author: noamokman

lib/pem.js

@@ -534,28 +534,38 @@ function spawnOpenSSL(params, callback) {
     // making this fail periodically.
     var needed = 2;  // wait for both exit and close.
     var code = -1;
-    var bothDone = function() {
-        if (code) {
-            callback(new Error("Invalid openssl exit code: " + code + "\n% openssl " + params.join(" ") + "\n" + stderr), code);
-        } else {
-            callback(null, code, stdout, stderr);
+    var finished = false;
+    var done = function (err) {
+        if (finished) {
+            return;
+        }
+
+        if (err) {
+            finished = true;
+            return callback(err);
+        }
+
+        if (--needed < 1) {
+            finished = true;
+            if (code) {
+                callback(new Error("Invalid openssl exit code: " + code + "\n% openssl " + params.join(" ") + "\n" + stderr), code);
+            } else {
+                callback(null, code, stdout, stderr);
+            }
         }
     };
 
+    openssl.on('error', done);
+
     openssl.on('exit', function (ret) {
         code = ret;
-        if (--needed < 1) {
-            bothDone();
-        }
+        done();
     });
 
     openssl.on('close', function () {
         stdout = new Buffer(stdout, "binary").toString("utf-8");
         stderr = new Buffer(stderr, "binary").toString("utf-8");
-
-        if (--needed < 1) {
-            bothDone();
-        }
+        done();
     });
 }