FELIX-2101: Exception in grep command

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@953295 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/karaf/shell/commands/pom.xml b/karaf/shell/commands/pom.xml
index 6448d62..fa02b72 100644
--- a/karaf/shell/commands/pom.xml
+++ b/karaf/shell/commands/pom.xml
@@ -54,6 +54,11 @@
             <artifactId>org.osgi.core</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/karaf/shell/commands/src/main/java/org/apache/felix/karaf/shell/commands/GrepAction.java b/karaf/shell/commands/src/main/java/org/apache/felix/karaf/shell/commands/GrepAction.java
index 4d26cef..2635eb6 100644
--- a/karaf/shell/commands/src/main/java/org/apache/felix/karaf/shell/commands/GrepAction.java
+++ b/karaf/shell/commands/src/main/java/org/apache/felix/karaf/shell/commands/GrepAction.java
@@ -172,7 +172,7 @@
                 } else {
                     firstPrint = false;
                 }
-                for (int i = 0; i < lineMatch + after; i++) {
+                for (int i = 0; i < lineMatch + after && i < lines.size(); i++) {
                     System.out.println(lines.get(i));
                 }
             }
diff --git a/karaf/shell/commands/src/test/java/org/apache/felix/karaf/shell/commands/GrepTest.java b/karaf/shell/commands/src/test/java/org/apache/felix/karaf/shell/commands/GrepTest.java
new file mode 100644
index 0000000..0469d64
--- /dev/null
+++ b/karaf/shell/commands/src/test/java/org/apache/felix/karaf/shell/commands/GrepTest.java
@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.felix.karaf.shell.commands;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.util.Arrays;
+
+import junit.framework.TestCase;
+import org.apache.felix.gogo.commands.basic.DefaultActionPreparator;
+
+public class GrepTest extends TestCase {
+
+    public void testGrep() throws Exception {
+        InputStream input = System.in;
+        try {
+            ByteArrayInputStream bais = new ByteArrayInputStream("1\n2\n3\n4\n5\n6\n7\n8\n9\n".getBytes());
+            System.setIn(bais);
+
+            GrepAction grep = new GrepAction();
+            DefaultActionPreparator preparator = new DefaultActionPreparator();
+            preparator.prepare(grep, null, Arrays.<Object>asList("-C", "100", "2"));
+            grep.doExecute();
+        } finally {
+            System.setIn(input);
+        }
+    }
+}