[fix] Add guards to every throw-able res.end call

lib/node-http-proxy/http-proxy.js

@@ -178,7 +178,8 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
       }
     }
 
-    res.end();
+    try { res.end() }
+    catch (ex) { console.error("res.end error: %s", ex.message) }
   }
 
   //
@@ -209,7 +210,9 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
 
     // If `response.statusCode === 304`: No 'data' event and no 'end'
     if (response.statusCode === 304) {
-      return res.end();
+      try { res.end() }
+      catch (ex) { console.error("res.end error: %s", ex.message) }
+      return;
     }
 
     //
@@ -223,9 +226,10 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
         try {
           res.write(chunk);
         } 
-        catch (er) {
+        catch (ex) {
+          console.error("res.write error: %s", ex.message);
           try { res.end() } 
-          catch (er) {}
+          catch (ex) { console.error("res.write error: %s", ex.message) }
         }
       }
     });
@@ -240,8 +244,10 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
     response.on('end', function () {
       if (!errState) {
         reverseProxy.removeListener('error', proxyError);
-        res.end();
-
+        
+        try { res.end() }
+        catch (ex) { console.error("res.end error: %s", ex.message) }
+        
         // Emit the `end` event now that we have completed proxying
         self.emit('end', req, res);
       }