root directory support

org.springframework.build.aws.maven/src/main/java/org/springframework/aws/maven/SimpleStorageServiceWagon.java

diff --git a/org.springframework.build.aws.maven/src/main/java/org/springframework/aws/maven/SimpleStorageServiceWagon.java b/org.springframework.build.aws.maven/src/main/java/org/springframework/aws/maven/SimpleStorageServiceWagon.java
index 21ece65..2a3c942 100644
--- a/org.springframework.build.aws.maven/src/main/java/org/springframework/aws/maven/SimpleStorageServiceWagon.java
+++ b/org.springframework.build.aws.maven/src/main/java/org/springframework/aws/maven/SimpleStorageServiceWagon.java
@@ -207,7 +207,7 @@
     private String getBaseDir(Repository source) {
         StringBuilder sb = new StringBuilder(source.getBasedir());
         sb.deleteCharAt(0);
-        if (sb.charAt(sb.length() - 1) != '/') {
+        if (sb.length()>0 && sb.charAt(sb.length() - 1) != '/') {
             sb.append('/');
         }
         return sb.toString();