Fix freezing on VM shutdown

src/QEMUVM.ts

@@ -55,6 +55,10 @@ export default class QEMUVM extends EventEmitter {
         this.processRestartErrorLevel = 0;
         this.expectedExit = false;
         this.qmpClient = new QMPClient(this.qmpSock, this.qmpType);
+        this.qmpClient.on('qmpshutdown', () => {
+            console.log("[INFO] QEMU requested shutdown, restarting...");
+            this.Restore();
+        });
         this.qmpClient.on('connected', () => this.qmpConnected());
         this.qmpClient.on('close', () => this.qmpClosed());
     }

src/QMPClient.ts

@@ -65,7 +65,20 @@ export default class QMPClient extends EventEmitter {
         }
         if (msg.return !== undefined)
             this.emit("qmpreturn", msg.return);
-        else
+        else if(msg.event !== undefined) {
+            switch(msg.event) {
+                case "POWERDOWN":
+                case "STOP":
+                {
+                    this.emit("qmpshutdown");
+                    break
+                };
+                default: {
+                    this.emit("qmpreturn", '');
+                    break;
+                }
+            }
+        }else
             // for now just return an empty string.
             // This is a giant hack but avoids a deadlock
             this.emit("qmpreturn", '');