adding sort option for build-classpath

src/it/projects/build-classpath-sorted/invoker.properties

@@ -0,0 +1,18 @@
+# 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.
+
+invoker.goals = ${project.groupId}:${project.artifactId}:${project.version}:build-classpath

src/it/projects/build-classpath-sorted/pom.xml

@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.its.dependency</groupId>
+  <artifactId>build-classpath-sorted</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>Test</name>
+  <description>
+    Test dependency:build-classpath -Dmdep.sortClasspath=true
+  </description>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-profile</artifactId>
+      <version>2.0.6</version>
+      <exclusions>
+        <exclusion>
+          <!-- NOTE: Excluded because of questionable handling of dependencyManagement in maven-profile:pom:2.0.6 -->
+          <groupId>classworlds</groupId>
+          <artifactId>classworlds</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+
+    <!-- one dependency with classifier -->
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-project</artifactId>
+      <version>2.0.6</version>
+      <classifier>sources</classifier>
+      <exclusions>
+        <exclusion>
+          <groupId>*</groupId>
+          <artifactId>*</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+  </dependencies>
+
+</project>

src/it/projects/build-classpath-sorted/test.properties

@@ -0,0 +1,22 @@
+# 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.
+
+mdep.outputFile = target/classpath.txt
+mdep.fileSeparator = /
+mdep.pathSeparator = :
+mdep.prefix = PREFIX
+mdep.sortClasspath = true

src/it/projects/build-classpath-sorted/verify.bsh

@@ -0,0 +1,33 @@
+/*
+ * 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.
+ */
+
+import java.io.File;
+
+import org.codehaus.plexus.util.FileUtils;
+import org.codehaus.plexus.util.StringUtils;
+
+String classpath = StringUtils.replace( FileUtils.fileRead( new File( basedir, "target/classpath.txt" ) ), "PREFIX/", "" );
+String expected = "junit-3.8.1.jar:maven-model-2.0.6.jar:maven-profile-2.0.6.jar:maven-project-2.0.6-sources.jar:plexus-container-default-1.0-alpha-9-stable-1.jar:plexus-utils-1.4.1.jar";
+
+if ( !classpath.equals( expected ) )
+{
+    throw new Exception( "Unexpected classpath: '" + classpath + "'" );
+}
+
+return true;

src/main/java/org/apache/maven/plugins/dependency/fromDependencies/BuildClasspathMojo.java

@@ -68,6 +68,12 @@ public class BuildClasspathMojo
     @Parameter( property = "outputEncoding", defaultValue = "${project.reporting.outputEncoding}" )
     private String outputEncoding;
 
+    /**
+     * Should the classpath be lexicographically sorted.
+     */
+    @Parameter( property = "mdep.sortClasspath", defaultValue = "false" )
+    private boolean sortClasspath = false;
+
     /**
      * Strip artifact version during copy (only works if prefix is set)
      */
@@ -197,6 +203,10 @@ protected void doExecute()
         }
 
         List<Artifact> artList = new ArrayList<>( artifacts );
+        if ( sortClasspath )
+        {
+            artList.sort( this );
+        }
 
         StringBuilder sb = new StringBuilder();
         Iterator<Artifact> i = artList.iterator();