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

Author: sultan

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

@@ -570,6 +570,13 @@ public final void parseVersion(String version) {
                 stack.push(list);
             } 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;
 
@@ -592,6 +599,13 @@ public final void parseVersion(String version) {
         }
 
         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

@@ -71,8 +71,8 @@ private Comparable newComparable(String version) {
     };
 
     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) {
@@ -346,4 +346,14 @@ public void testReuse() {
 
         assertEquals(c1, c2, "reused instance should be equivalent to new instance");
     }
+
+    /**
+     * Test <a href="https://issues.apache.org/jira/browse/MNG-7644">MNG-7644</a> edge cases
+     * 1.0.0.RC1 < 1.0.0-RC2
+     */
+    @Test
+    public void testMng7644() {
+        checkVersionsOrder("1.0.0.RC1", "1.0.0-RC2");
+        checkVersionsEqual("2.0.a", "2.0.0.a"); // previously ordered, now equals
+    }
 }