Index: CHANGES.txt
===================================================================
--- CHANGES.txt	(revision 1001906)
+++ CHANGES.txt	(working copy)
@@ -40,8 +40,15 @@
   if the writer had just committed (Nikolay Zamosenchuk via Mike McCandless)
 
 * LUCENE-2650: Added extra safety to MMapIndexInput clones to prevent accessing
-  an unmapped buffer if the input is closed (Mike McCandless, Uwe Schindler, Robert Muir) 
+  an unmapped buffer if the input is closed (Mike McCandless, Uwe Schindler, Robert Muir)
   
+New features
+
+* LUCENE-2675: Add support for Lucene 3.0 stored field files also in 2.9.
+  The file format did not change, only the version number was upgraded to mark
+  segments that have no compression. FieldsWriter still only writes 2.9 segments
+  as they could contain compressed fields. (Uwe Schindler)
+  
 Documentation
 
 * LUCENE-2239: Documented limitations in NIOFSDirectory and MMapDirectory due to
Index: src/java/org/apache/lucene/index/FieldsReader.java
===================================================================
--- src/java/org/apache/lucene/index/FieldsReader.java	(revision 1001906)
+++ src/java/org/apache/lucene/index/FieldsReader.java	(working copy)
@@ -113,7 +113,9 @@
       else
         format = firstInt;
 
-      if (format > FieldsWriter.FORMAT_CURRENT)
+      if (format > FieldsWriter.FORMAT_CURRENT
+        /* extra support for Lucene 3.0 indexes: */ && format != FieldsWriter.FORMAT_LUCENE_3_0_NO_COMPRESSED_FIELDS
+      )
         throw new CorruptIndexException("Incompatible format version: " + format + " expected " 
                                         + FieldsWriter.FORMAT_CURRENT + " or lower");
 
Index: src/java/org/apache/lucene/index/FieldsWriter.java
===================================================================
--- src/java/org/apache/lucene/index/FieldsWriter.java	(revision 1001906)
+++ src/java/org/apache/lucene/index/FieldsWriter.java	(working copy)
@@ -38,6 +38,12 @@
 
   // Changed strings to UTF8
   static final int FORMAT_VERSION_UTF8_LENGTH_IN_BYTES = 1;
+  
+  // Lucene 3.0: Removal of compressed fields: This is only to provide compatibility with 3.0-created indexes
+  // new segments always use the FORMAT_CURRENT. As the index format did not change in 3.0, only
+  // new stored field files that no longer support compression are marked as such to optimize merging.
+  // But 2.9 can still read them.
+  static final int FORMAT_LUCENE_3_0_NO_COMPRESSED_FIELDS = 2;
 
   // NOTE: if you introduce a new format, make it 1 higher
   // than the current one, and always change this if you
Index: src/test/org/apache/lucene/index/index.30.cfs.zip
===================================================================
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream

Property changes on: src\test\org\apache\lucene\index\index.30.cfs.zip
___________________________________________________________________
Added: svn:mime-type
   + application/octet-stream

Index: src/test/org/apache/lucene/index/index.30.nocfs.zip
===================================================================
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream

Property changes on: src\test\org\apache\lucene\index\index.30.nocfs.zip
___________________________________________________________________
Added: svn:mime-type
   + application/octet-stream

Index: src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
===================================================================
--- src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(revision 1001906)
+++ src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(working copy)
@@ -128,6 +128,8 @@
                              "23.nocfs",
                              "24.cfs",
                              "24.nocfs",
+                             "30.cfs",
+                             "30.nocfs",
   };
 
   public void testOptimizeOldIndex() throws IOException {