[MENFORCER-440] Fix pattern for Java 8 version

Author: slawekjaranowski

enforcer-rules/src/main/java/org/apache/maven/enforcer/rules/version/RequireJavaVersion.java

@@ -42,7 +42,7 @@
 @Named("requireJavaVersion")
 public final class RequireJavaVersion extends AbstractVersionEnforcer {
 
-    private static final Pattern JDK8_VERSION_PATTERN = Pattern.compile("([\\[(,]?)(1\\.8|8)([]),]?)");
+    private static final Pattern JDK8_VERSION_PATTERN = Pattern.compile("([\\d.]+)");
 
     /**
      * Display the normalized JDK version.
@@ -57,11 +57,20 @@ public void setVersion(String theVersion) {
             return;
         }
 
+        if (!theVersion.contains("8")) {
+            super.setVersion(theVersion);
+            return;
+        }
+
         Matcher matcher = JDK8_VERSION_PATTERN.matcher(theVersion);
 
         StringBuffer result = new StringBuffer();
         while (matcher.find()) {
-            matcher.appendReplacement(result, "$11.8$3");
+            if ("8".equals(matcher.group(1))) {
+                matcher.appendReplacement(result, "1.8");
+            } else {
+                matcher.appendReplacement(result, "$1");
+            }
         }
         matcher.appendTail(result);
 

enforcer-rules/src/test/java/org/apache/maven/enforcer/rules/version/TestRequireJavaVersion.java

@@ -140,14 +140,24 @@ static Stream<Arguments> fixJava8ShortVersion() {
         return Stream.of(
                 Arguments.of("1.8", "1.8"),
                 Arguments.of("8", "1.8"),
+                Arguments.of(".8", ".8"),
+                Arguments.of("8.", "8."),
                 Arguments.of("8,)", "1.8,)"),
                 Arguments.of("[8,)", "[1.8,)"),
                 Arguments.of("(1.7,8]", "(1.7,1.8]"),
                 Arguments.of("[1.8,)", "[1.8,)"),
                 Arguments.of("(1.8,8]", "(1.8,1.8]"),
+                Arguments.of("(8,8]", "(1.8,1.8]"),
                 Arguments.of("(8,)", "(1.8,)"),
                 Arguments.of("[8]", "[1.8]"),
-                Arguments.of("(9,11],[8]", "(9,11],[1.8]"));
+                Arguments.of("(9,11],[8]", "(9,11],[1.8]"),
+                Arguments.of("(11.0.18", "(11.0.18"),
+                Arguments.of("(15.1.8", "(15.1.8"),
+                Arguments.of("(15.1.2", "(15.1.2"),
+                Arguments.of("18", "18"),
+                Arguments.of("18.", "18."),
+                Arguments.of(".18", ".18"),
+                Arguments.of("38", "38"));
     }
 
     @ParameterizedTest