Ignoring dependency with no version in useReleases

Closes #584 #584

src/it/it-use-releases-issue-583/invoker.properties

@@ -0,0 +1 @@
+invoker.goals=${project.groupId}:${project.artifactId}:${project.version}:use-releases -DallowRangeMatching=true -DfailIfNotReplaced=true

src/it/it-use-releases-issue-583/pom.xml

@@ -0,0 +1,21 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>localhost</groupId>
+  <artifactId>it-use-releases-issue-583</artifactId>
+  <version>1.0</version>
+  <packaging>pom</packaging>
+  <name>Skip a dependency without version</name>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>localhost</groupId>
+        <artifactId>dummy-api</artifactId>
+        <scope>provided</scope>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+</project>

src/it/it-use-releases-issue-583/verify.bsh

@@ -0,0 +1,23 @@
+import java.io.*;
+import org.codehaus.plexus.util.FileUtils;
+import java.util.regex.*;
+
+try
+{
+    File file = new File( basedir, "build.log" );
+    String buf = FileUtils.fileRead( file );
+    Pattern p = Pattern.compile( "\\QIgnoring dependency with no version: localhost:dummy-api:jar\\E" );
+    Matcher m = p.matcher( buf.toString() );
+    if ( !m.find() )
+    {
+        System.out.println( "cannot find skipping of dummy-api dependency" );
+        return false;
+    }
+}
+catch( Throwable t )
+{
+    t.printStackTrace();
+    return false;
+}
+
+return true;

src/main/java/org/codehaus/mojo/versions/AbstractVersionsDependencyUpdaterMojo.java

@@ -188,10 +188,11 @@ public boolean isExcludeReactor()
      * @return true if the version starts with '${'
      * @since 2.8
      */
-    protected boolean isHandledByProperty(Dependency dependency) {
-		String version = dependency.getVersion();
-		return version.startsWith("${");
-	}
+    protected boolean isHandledByProperty( Dependency dependency )
+    {
+        String version = dependency.getVersion();
+        return version != null && version.startsWith( "${" );
+    }
 
     /**
      * Try to find the dependency artifact that matches the given dependency.

src/main/java/org/codehaus/mojo/versions/UseReleasesMojo.java

@@ -209,6 +209,11 @@ private void useReleases( ModifiedPomXMLEventReader pom, Collection<Dependency>
             }
 
             String version = dep.getVersion();
+            if ( version == null )
+            {
+                getLog().info( "Ignoring dependency with no version: " + toString( dep ) );
+                continue;
+            }
             Matcher versionMatcher = matchSnapshotRegex.matcher( version );
             if ( versionMatcher.matches() )
             {