Always specify AT_UNNAMED when opening unnamed stream with libntfs-3g

[wimlib] / src / ntfs-3g_apply.c

diff --git a/src/ntfs-3g_apply.c b/src/ntfs-3g_apply.c
index 07dbdf65094df0e05c865b202b455b5b2f3e18d0..148abc769f058373ad5f350cfad773ae0c269bc7 100644 (file)
--- a/src/ntfs-3g_apply.c
+++ b/src/ntfs-3g_apply.c
@@ -714,6 +714,7 @@ ntfs_3g_begin_extract_blob_instance(struct blob_descriptor *blob,
                                    struct ntfs_3g_apply_ctx *ctx)
 {
        struct wim_dentry *one_dentry = inode_first_extraction_dentry(inode);
+       ntfschar *stream_name;
        size_t stream_name_nchars;
        ntfs_attr *attr;
 
@@ -736,22 +737,29 @@ ntfs_3g_begin_extract_blob_instance(struct blob_descriptor *blob,
        /* It's a data stream (may be unnamed or named).  */
        wimlib_assert(strm->stream_type == STREAM_TYPE_DATA);
 
-       stream_name_nchars = utf16le_len_chars(strm->stream_name);
+       if (unlikely(stream_is_named(strm))) {
+               stream_name = strm->stream_name;
+               stream_name_nchars = utf16le_len_chars(stream_name);
 
-       if (stream_name_nchars &&
-           (ntfs_attr_add(ni, AT_DATA, strm->stream_name,
-                          stream_name_nchars, NULL, 0)))
-       {
-               ERROR_WITH_ERRNO("Failed to create named data stream of \"%s\"",
-                                dentry_full_path(one_dentry));
-               return WIMLIB_ERR_NTFS_3G;
+               if (ntfs_attr_add(ni, AT_DATA, stream_name,
+                                 stream_name_nchars, NULL, 0))
+               {
+                       ERROR_WITH_ERRNO("Failed to create named data stream of \"%s\"",
+                                        dentry_full_path(one_dentry));
+                       return WIMLIB_ERR_NTFS_3G;
+               }
+       } else {
+               /* Don't pass an empty string other than AT_UNNAMED to
+                * ntfs_attr_open() --- it violates assumptions made by
+                * libntfs-3g.  */
+               stream_name = AT_UNNAMED;
+               stream_name_nchars = 0;
        }
 
        /* This should be ensured by extract_blob_list()  */
        wimlib_assert(ctx->num_open_attrs < MAX_OPEN_FILES);
 
-       attr = ntfs_attr_open(ni, AT_DATA, strm->stream_name,
-                             stream_name_nchars);
+       attr = ntfs_attr_open(ni, AT_DATA, stream_name, stream_name_nchars);
        if (!attr) {
                ERROR_WITH_ERRNO("Failed to open data stream of \"%s\"",
                                 dentry_full_path(one_dentry));