Forbid modifying multi-referenced images

[wimlib] / src / update_image.c

diff --git a/src/update_image.c b/src/update_image.c
index 49492a3f54aa286ae74f21a3c697a678ee0ea3fa..66e5ed8d4157a3c23300cbcbafb043324060c71f 100644 (file)
--- a/src/update_image.c
+++ b/src/update_image.c
@@ -1396,6 +1396,7 @@ wimlib_update_image(WIMStruct *wim,
                    int update_flags)
 {
        int ret;
+       struct wim_image_metadata *imd;
        struct wimlib_update_command *cmds_copy;
 
        if (update_flags & ~WIMLIB_UPDATE_FLAG_SEND_PROGRESS)
@@ -1404,7 +1405,14 @@ wimlib_update_image(WIMStruct *wim,
        /* Load the metadata for the image to modify (if not loaded already) */
        ret = select_wim_image(wim, image);
        if (ret)
-               goto out;
+               return ret;
+
+       imd = wim->image_metadata[image - 1];
+
+       /* Don't allow updating an image currently being shared by multiple
+        * WIMStructs (as a result of an export)  */
+       if (imd->refcnt > 1)
+               return WIMLIB_ERR_IMAGE_HAS_MULTIPLE_REFERENCES;
 
        /* Make a copy of the update commands, in the process doing certain
         * canonicalizations on paths (e.g. translating backslashes to forward
@@ -1412,7 +1420,7 @@ wimlib_update_image(WIMStruct *wim,
         * commands. */
        ret = copy_update_commands(cmds, num_cmds, &cmds_copy);
        if (ret)
-               goto out;
+               return ret;
 
        /* Perform additional checks on the update commands before we execute
         * them. */
@@ -1425,7 +1433,7 @@ wimlib_update_image(WIMStruct *wim,
        if (ret)
                goto out_free_cmds_copy;
 
-       mark_image_dirty(wim->image_metadata[image - 1]);
+       mark_image_dirty(imd);
 
        /* Statistics about the WIM image, such as the numbers of files and
         * directories, may have changed.  Call xml_update_image_info() to
@@ -1438,7 +1446,6 @@ wimlib_update_image(WIMStruct *wim,
                        wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 out_free_cmds_copy:
        free_update_commands(cmds_copy, num_cmds);
-out:
        return ret;
 }