[MSHARED-1014] Optionally inherit system environment variables by Commandline

src/main/java/org/apache/maven/shared/utils/cli/Commandline.java

@@ -65,12 +65,14 @@
 public class Commandline
     implements Cloneable
 {
-    private final List<Arg> arguments = new Vector<Arg>();
+    private final List<Arg> arguments = new Vector<>();
 
     private final Map<String, String> envVars = Collections.synchronizedMap( new LinkedHashMap<String, String>() );
 
     private Shell shell;
 
+    private boolean shellEnvironmentInherited = true;
+
     /**
      * Create a new command line object.
      * Shell is autodetected from operating system.
@@ -198,14 +200,13 @@ public void addArguments( String... line )
      */
     public void addEnvironment( String name, String value )
     {
-        //envVars.add( name + "=" + value );
         envVars.put( name, value );
     }
 
     /**
      * Add system environment variables.
      */
-    public void addSystemEnvironment()
+    private void addSystemEnvironment()
     {
         Properties systemEnvVars = CommandLineUtils.getSystemEnvVars();
 
@@ -226,7 +227,11 @@ public void addSystemEnvironment()
      */
     public String[] getEnvironmentVariables()
     {
-        addSystemEnvironment();
+        if ( isShellEnvironmentInherited() )
+        {
+            addSystemEnvironment();
+        }
+
         List<String> environmentVars = new ArrayList<>();
         for ( String name : envVars.keySet() )
         {
@@ -297,7 +302,7 @@ public String[] getArguments()
      */
     public String[] getArguments( boolean mask )
     {
-        List<String> result = new ArrayList<String>( arguments.size() * 2 );
+        List<String> result = new ArrayList<>( arguments.size() * 2 );
         for ( Arg argument : arguments )
         {
             Argument arg = (Argument) argument;
@@ -377,6 +382,29 @@ public void clearArgs()
         arguments.clear();
     }
 
+    /**
+     * Indicates whether the environment variables of the current process
+     * should are propagated to the executing Command.
+     * By default, the current environment variables are inherited by the new Command line execution.
+     *
+     * @return <code>true</code> if the environment variables should be propagated, <code>false</code> otherwise.
+     */
+    public boolean isShellEnvironmentInherited()
+    {
+        return shellEnvironmentInherited;
+    }
+
+    /**
+     * Specifies whether the environment variables of the current process should be propagated to the executing Command.
+     *
+     * @param shellEnvironmentInherited <code>true</code> if the environment variables should be propagated,
+     *            <code>false</code> otherwise.
+     */
+    public void setShellEnvironmentInherited( boolean shellEnvironmentInherited )
+    {
+        this.shellEnvironmentInherited = shellEnvironmentInherited;
+    }
+
     /**
      * Execute the command.
      * 

src/test/java/org/apache/maven/shared/utils/cli/CommandLineUtilsTest.java

@@ -56,9 +56,8 @@ public void testGetSystemEnvVarsCaseInsensitive()
 
     @Test
     public void testEnsureCaseSensitivity()
-        throws Exception
     {
-        Map<String, String> data = new HashMap<String, String>();
+        Map<String, String> data = new HashMap<>();
         data.put( "abz", "cool" );
         assertTrue( CommandLineUtils.ensureCaseSensitivity( data, false ).containsKey( "ABZ" ) );
         assertTrue( CommandLineUtils.ensureCaseSensitivity( data, true ).containsKey( "abz" ) );
@@ -69,7 +68,6 @@ public void testEnsureCaseSensitivity()
      */
     @Test
     public void testGetSystemEnvVarsWindows()
-        throws Exception
     {
         if ( !Os.isFamily( Os.FAMILY_WINDOWS ) )
         {
@@ -103,14 +101,9 @@ public void testTranslateCommandline()
         assertCmdLineArgs( new String[] { "foo", " ' ", "bar" }, "foo \" ' \" bar" );
     }
 
-
     @Test
-    public void givenASingleQuoteMarkInArgument_whenExecutingCode_thenNoExceptionIsThrown() throws Exception {
-        new Commandline("echo \"let's go\"").execute();
-    }
-
-    @Test
-    public void givenADoubleQuoteMarkInArgument_whenExecutingCode_thenCommandLineExceptionIsThrown() throws Exception {
+    public void givenADoubleQuoteMarkInArgument_whenExecutingCode_thenCommandLineExceptionIsThrown()
+    {
         try {
             new Commandline("echo \"let\"s go\"").execute();
         } catch (CommandLineException e) {
@@ -124,8 +117,7 @@ public void givenADoubleQuoteMarkInArgument_whenExecutingCode_thenCommandLineExc
     @Test
     public void givenASingleQuoteMarkInArgument_whenExecutingCode_thenExitCode0Returned() throws Exception {
         final Process p = new Commandline("echo \"let's go\"").execute();
-        // Note, this sleep should be removed when java version reaches Java 8
-        Thread.sleep(1000);
+        p.waitFor();
         assertEquals(0, p.exitValue());
     }
 
@@ -160,7 +152,9 @@ public void givenAnEscapedSingleQuoteMarkInArgument_whenTranslatingToCmdLineArgs
     public void givenAnEscapedDoubleQuoteMarkInArgument_whenTranslatingToCmdLineArgs_thenNoExceptionIsThrown()
         throws Exception
     {
-        new Commandline( "echo \"let\\\"s go\"" ).execute();
+        Process p = new Commandline( "echo \"let\\\"s go\"" ).execute();
+        p.waitFor();
+        assertEquals(0, p.exitValue());
     }
 
     private void assertCmdLineArgs( final String[] expected, final String cmdLine )
@@ -185,7 +179,7 @@ public void environmentVariableWithNullShouldNotBeSet() {
     }
 
     @Test
-    public void environmentVariableFromSystemIsCopied() {
+    public void environmentVariableFromSystemIsCopiedByDefault() {
 
         Commandline commandline = new Commandline();
 
@@ -195,6 +189,18 @@ public void environmentVariableFromSystemIsCopied() {
         assertThat(environmentVariables, hasItemInArray( "TEST_SHARED_ENV=TestValue" ) );
     }
 
+    @Test
+    public void environmentVariableFromSystemIsNotCopiedIfInheritedIsFalse() {
+
+        Commandline commandline = new Commandline();
+        commandline.setShellEnvironmentInherited( false );
+
+        String[] environmentVariables = commandline.getEnvironmentVariables();
+
+        assertNotNull(environmentVariables);
+        assertEquals(0, environmentVariables.length );
+    }
+
     @Test
     public void environmentVariableFromSystemIsRemoved() {