SOLR-1577: fix data dir default to stay under solr home

git-svn-id: https://svn.apache.org/repos/asf/lucene/solr/trunk@883202 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -64,6 +64,12 @@ Bug Fixes
 * SOLR-1563: Binary fields, including trie-based numeric fields, caused null
   pointer exceptions in the luke request handler. (yonik)
 
+* SOLR-1577: The example solrconfig.xml defaulted to a solr data dir
+  relative to the current working directory, even if a different solr home
+  was being used.  The new behavior changes the default to a zero length
+  string, which is treated the same as if no dataDir had been specified,
+  hence the "data" directory under the solr home will be used.  (yonik)
+
 
 Other Changes
 ----------------------

example/solr/conf/solrconfig.xml

@@ -68,7 +68,7 @@
   <!-- Used to specify an alternate directory to hold all index data
        other than the default ./data under the Solr home.
        If replication is in use, this should match the replication configuration. -->
-  <dataDir>${solr.data.dir:./solr/data}</dataDir>
+  <dataDir>${solr.data.dir:}</dataDir>
 
 
   <!-- WARNING: this <indexDefaults> section only provides defaults for index writers

src/java/org/apache/solr/core/CoreDescriptor.java

@@ -109,6 +109,8 @@ public class CoreDescriptor {
 
   public void setDataDir(String s) {
     dataDir = s;
+    // normalize zero length to null.
+    if (dataDir != null && dataDir.length()==0) dataDir=null;
   }
 
   /**@return the core instance directory. */

src/java/org/apache/solr/core/SolrConfig.java

@@ -160,6 +160,7 @@ public class SolrConfig extends Config {
     unlockOnStartup = getBool("mainIndex/unlockOnStartup", false);
     useColdSearcher = getBool("query/useColdSearcher",false);
     dataDir = get("dataDir", null);
+    if (dataDir != null && dataDir.length()==0) dataDir=null;
 
     userCacheConfigs = CacheConfig.getMultipleConfigs(this, "query/cache");