[MNG-7644] Fix version comparison ( .RC1 < -RC2 )

Author: sultan

maven-artifact/src/main/java/org/apache/maven/artifact/versioning/ComparableVersion.java

@@ -676,6 +676,14 @@ else if ( Character.isDigit( c ) )
             {
                 if ( !isDigit && i > startIndex )
                 {
+                    // 1.0.0.RC1 < 1.0.0-RC2
+                    // treat .RC as -RC
+                    if ( !list.isEmpty() )
+                    {
+                        list.add( list = new ListItem() );
+                        stack.push( list );
+                    }
+
                     list.add( new StringItem( version.substring( startIndex, i ), true ) );
                     startIndex = i;
 
@@ -702,6 +710,14 @@ else if ( Character.isDigit( c ) )
 
         if ( version.length() > startIndex )
         {
+            // 1.0.0.RC1 < 1.0.0-RC2
+            // treat .RC as -RC
+            if ( !isDigit && !list.isEmpty() )
+            {
+                list.add( list = new ListItem() );
+                stack.push( list );
+            }
+
             list.add( parseItem( isDigit, version.substring( startIndex ) ) );
         }
 

maven-artifact/src/test/java/org/apache/maven/artifact/versioning/ComparableVersionTest.java

@@ -51,8 +51,8 @@ private Comparable newComparable( String version )
             "1-1", "1-2", "1-123" };
 
     private static final String[] VERSIONS_NUMBER =
-        { "2.0", "2-1", "2.0.a", "2.0.0.a", "2.0.2", "2.0.123", "2.1.0", "2.1-a", "2.1b", "2.1-c", "2.1-1", "2.1.0.1",
-            "2.2", "2.123", "11.a2", "11.a11", "11.b2", "11.b11", "11.m2", "11.m11", "11", "11.a", "11b", "11c", "11m" };
+        { "2.0", "2.0.a", "2-1", "2.0.2", "2.0.123", "2.1.0", "2.1-a", "2.1b", "2.1-c", "2.1-1", "2.1.0.1", "2.2",
+            "2.123", "11.a2", "11.a11", "11.b2", "11.b11", "11.m2", "11.m11", "11", "11.a", "11b", "11c", "11m" };
 
     private void checkVersionsOrder( String[] versions )
     {
@@ -337,4 +337,14 @@ public void testReuse()
 
         assertEquals( "reused instance should be equivalent to new instance", c1, c2 );
     }
+
+    /**
+     * Test <a href="https://issues.apache.org/jira/browse/MNG-7644">MNG-7644</a> edge cases
+     * 1.0.0.RC1 < 1.0.0-RC2
+     */
+    public void testMng7644()
+    {
+        checkVersionsOrder( "1.0.0.RC1", "1.0.0-RC2" );
+        checkVersionsEqual( "2.0.a", "2.0.0.a" ); // previously ordered, now equals
+    }
 }