dentry.c: correctly read empty reparse stream
authorEric Biggers <ebiggers3@gmail.com>
Tue, 23 Jun 2015 05:19:12 +0000 (00:19 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Thu, 25 Jun 2015 03:39:37 +0000 (22:39 -0500)
src/dentry.c

index 5c6f975..8b00da1 100644 (file)
@@ -1227,6 +1227,12 @@ assign_stream_types_encrypted(struct wim_inode *inode)
  * There will be an unnamed data stream, a reparse point stream, or both an
  * unnamed data stream and a reparse point stream.  In addition, there may be
  * named data streams.
+ *
+ * NOTE: if the file has a reparse point stream or at least one named data
+ * stream, then WIMGAPI puts *all* streams in the extra stream entries and
+ * leaves the default stream hash zeroed.  wimlib now does the same.  However,
+ * for input we still support the default hash field being used, since wimlib
+ * used to use it and MS software is somewhat accepting of it as well.
  */
 static void
 assign_stream_types_unencrypted(struct wim_inode *inode)
@@ -1241,7 +1247,10 @@ assign_stream_types_unencrypted(struct wim_inode *inode)
                if (stream_is_named(strm)) {
                        /* Named data stream  */
                        strm->stream_type = STREAM_TYPE_DATA;
-               } else if (!is_zero_hash(strm->_stream_hash)) {
+               } else if (i != 0 || !is_zero_hash(strm->_stream_hash)) {
+                       /* Unnamed stream in the extra stream entries, OR the
+                        * default stream in the dentry provided that it has a
+                        * nonzero hash.  */
                        if ((inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
                            !found_reparse_point_stream) {
                                found_reparse_point_stream = true;
@@ -1250,17 +1259,21 @@ assign_stream_types_unencrypted(struct wim_inode *inode)
                                found_unnamed_data_stream = true;
                                strm->stream_type = STREAM_TYPE_DATA;
                        }
-               } else {
-                       /* If no stream name is specified and the hash is zero,
-                        * then remember this stream for later so that we can
-                        * assign it to the unnamed data stream if we don't find
-                        * a better candidate.  */
+               } else if (!unnamed_stream_with_zero_hash) {
                        unnamed_stream_with_zero_hash = strm;
                }
        }
 
-       if (!found_unnamed_data_stream && unnamed_stream_with_zero_hash != NULL)
-               unnamed_stream_with_zero_hash->stream_type = STREAM_TYPE_DATA;
+       if (unnamed_stream_with_zero_hash) {
+               int type = STREAM_TYPE_UNKNOWN;
+               if ((inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
+                   !found_reparse_point_stream) {
+                       type = STREAM_TYPE_REPARSE_POINT;
+               } else if (!found_unnamed_data_stream) {
+                       type = STREAM_TYPE_DATA;
+               }
+               unnamed_stream_with_zero_hash->stream_type = type;
+       }
 }
 
 /*