Add a test for parsing the thread configuration with the core multiplier

maven-embedder/src/main/java/org/apache/maven/cli/MavenCli.java

@@ -1094,7 +1094,7 @@ public class MavenCli
 
             if ( threadConfiguration.contains( "C" ) )
             {
-                request.setDegreeOfConcurrency( (int) ( Float.valueOf( threadConfiguration.replace( "C", "" ) ) * Runtime.getRuntime().availableProcessors() ) );
+                request.setDegreeOfConcurrency( calculateDegreeOfConcurrencyWithCoreMultiplier( threadConfiguration ) );
             }
             else
             {
@@ -1113,6 +1113,11 @@ public class MavenCli
         return request;
     }
 
+    int calculateDegreeOfConcurrencyWithCoreMultiplier( String threadConfiguration )
+    {
+        return (int) ( Float.valueOf( threadConfiguration.replace( "C", "" ) ) * Runtime.getRuntime().availableProcessors() );
+    }
+    
     static File resolveFile( File file, String workingDirectory )
     {
         if ( file == null )

maven-embedder/src/test/java/org/apache/maven/cli/MavenCliTest.java

@@ -0,0 +1,32 @@
+package org.apache.maven.cli;
+
+import junit.framework.TestCase;
+
+public class MavenCliTest extends TestCase 
+{
+    private MavenCli cli;
+    
+    protected void setUp()
+    {
+        cli = new MavenCli();  
+    }
+    
+    public void testCalculateDegreeOfConcurrencyWithCoreMultiplier()
+    {
+        int cores = Runtime.getRuntime().availableProcessors();        
+        // -T2.2C
+        assertEquals((int)(cores * 2.2), cli.calculateDegreeOfConcurrencyWithCoreMultiplier("C2.2"));
+        // -TC2.2
+        assertEquals((int)(cores * 2.2), cli.calculateDegreeOfConcurrencyWithCoreMultiplier("2.2C"));
+        
+        try
+        {
+            cli.calculateDegreeOfConcurrencyWithCoreMultiplier("CXXX");
+            fail("Should have failed with a NumberFormatException");
+        } 
+        catch( NumberFormatException e) 
+        {
+            // carry on
+        }        
+    }    
+}