From 5c848ce17a0d02a0cb61b14e2739e14b6cf5f843 Mon Sep 17 00:00:00 2001
From: Benjamin Bentmann <bentmann@apache.org>
Date: Thu, 20 Aug 2009 18:17:26 +0000
Subject: [PATCH] [MNG-4312] Magic expressions injected by
 PluginParameterExpressionEvalutor conflict with expressions used by plugins
 to access system properties

git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@806286 13f79535-47bb-0310-9956-ffa450edef68
---
 .../PluginParameterExpressionEvaluator.java   | 23 +++++++++++++++++--
 pom.xml                                       |  2 +-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluator.java b/maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluator.java
index 2acbf350c9..8739f9fd89 100644
--- a/maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluator.java
+++ b/maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluator.java
@@ -28,7 +28,7 @@
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.path.PathTranslator;
 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
-import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
+import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
 import org.codehaus.plexus.logging.Logger;
 import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;
 
@@ -36,7 +36,7 @@
  * @author Jason van Zyl
  */
 public class PluginParameterExpressionEvaluator
-    implements ExpressionEvaluator
+    implements TypeAwareExpressionEvaluator
 {
     private MavenSession session;
 
@@ -94,6 +94,12 @@ public PluginParameterExpressionEvaluator( MavenSession session, MojoExecution m
 
     public Object evaluate( String expr )
         throws ExpressionEvaluationException
+    {
+        return evaluate( expr, null );
+    }
+
+    public Object evaluate( String expr, Class<?> type )
+        throws ExpressionEvaluationException
     {
         Object value = null;
 
@@ -295,6 +301,19 @@ else if ( expression.startsWith( "basedir" ) )
             }
         }
 
+        /*
+         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
+         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to
+         * unintentionally use such a magic expression for an ordinary system property. So here we check whether we
+         * ended up with a magic value that is not compatible with the type of the configured mojo parameter (a string
+         * could still be converted by the configurator so we leave those alone). If so, back off to evaluating the
+         * expression from properties only.
+         */
+        if ( value != null && type != null && !( value instanceof String ) && !type.isInstance( value ) )
+        {
+            value = null;
+        }
+
         if ( value == null )
         {
             // The CLI should win for defining properties
diff --git a/pom.xml b/pom.xml
index 8fcec15816..2eff1cc2f9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -42,7 +42,7 @@
     <commonsCliVersion>1.2</commonsCliVersion>
     <easyMockVersion>1.2_Java1.3</easyMockVersion>
     <junitVersion>3.8.2</junitVersion>
-    <plexusVersion>1.1.0</plexusVersion>
+    <plexusVersion>1.2.0</plexusVersion>
     <plexusInterpolationVersion>1.11</plexusInterpolationVersion>
     <plexusPluginManagerVersion>1.0-alpha-1</plexusPluginManagerVersion>
     <plexusUtilsVersion>1.5.15</plexusUtilsVersion>