fix a crash when timeout in Exec

AndroidManifest.xml

@@ -2,8 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.github.shadowsocks"
           android:installLocation="auto"
-          android:versionCode="7"
-          android:versionName="1.1.3">
+          android:versionCode="8"
+          android:versionName="1.1.4">
 
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

pom.xml

@@ -4,7 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.github.shadowsocks</groupId>
     <artifactId>shadowsocks</artifactId>
-    <version>1.1.3</version>
+    <version>1.1.4</version>
     <packaging>apk</packaging>
     <name>Shadowsocks</name>
 

src/com/github/shadowsocks/Utils.java

@@ -271,6 +271,21 @@ public class Utils {
         private final boolean asroot;
         public int exitcode = -1;
 
+        private int[] pid = new int[1];
+        private FileDescriptor pipe;
+
+        @Override
+        public void destroy() {
+            if (pid[0] != -1) {
+                Exec.hangupProcessGroup(pid[0]);
+                pid[0] = -1;
+            }
+            if (pipe != null) {
+                Exec.close(pipe);
+                pipe = null;
+            }
+        }
+
         /**
          * Creates a new script runner.
          *
@@ -344,8 +359,6 @@ public class Utils {
 
         @Override
         public void run() {
-            FileDescriptor pipe = null;
-            int pid[] = new int[1];
             pid[0] = -1;
 
             try {