From 0a36e611f24ca05f72d4547e2d6ab9364ac63ebd Mon Sep 17 00:00:00 2001
From: Jason van Zyl <jvanzyl@apache.org>
Date: Sun, 2 Sep 2007 23:21:23 +0000
Subject: [PATCH] o turn on envar support in 2.1, we just can't turn it off now
 at this point.

git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@572190 13f79535-47bb-0310-9956-ffa450edef68
---
 .../interpolation/RegexBasedModelInterpolator.java | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/maven-project/src/main/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolator.java b/maven-project/src/main/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolator.java
index b3ad3175b5..a93b7e623e 100644
--- a/maven-project/src/main/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolator.java
+++ b/maven-project/src/main/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolator.java
@@ -25,15 +25,15 @@ import org.apache.maven.model.io.xpp3.MavenXpp3Writer;
 import org.codehaus.plexus.logging.AbstractLogEnabled;
 import org.codehaus.plexus.logging.Logger;
 import org.codehaus.plexus.util.StringUtils;
+import org.codehaus.plexus.util.cli.CommandLineUtils;
 import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;
 import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
 
 import java.io.IOException;
 import java.io.StringReader;
 import java.io.StringWriter;
-import java.util.HashSet;
 import java.util.Map;
-import java.util.Set;
+import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -50,9 +50,12 @@ public class RegexBasedModelInterpolator
 {
     private static final Pattern EXPRESSION_PATTERN = Pattern.compile( "\\$\\{(pom\\.|project\\.|env\\.)?([^}]+)\\}" );
 
+    private Properties envars;
+
     public RegexBasedModelInterpolator()
         throws IOException
     {
+        envars = CommandLineUtils.getSystemEnvVars();                                                                                                        
     }
 
     public Model interpolate( Model model, Map context )
@@ -181,6 +184,11 @@ public class RegexBasedModelInterpolator
                 value = model.getProperties().getProperty( realExpr );
             }
 
+            if ( value == null )
+            {
+                value = envars.getProperty( realExpr );
+            }
+
             // Any expression, not just artifactId, version etc., but also scm.repository 
             // were evaluated against the model, even if there is no prefix.
             // If the 2.1 strategy fails, try the legacy approach. If it yields a result, warn for it.
@@ -213,6 +221,8 @@ public class RegexBasedModelInterpolator
                 // but this could result in multiple lookups of stringValue, and replaceAll is not correct behaviour
                 matcher.reset( result );
             }
+
+            
 /*
         // This is the desired behaviour, however there are too many crappy poms in the repo and an issue with the
         // timing of executing the interpolation