[tracker-miners/wip/carlosg/backport-fixes-3.0: 2/3] tracker-miner-fs: Fall back if no modification date is found

[Carlos Garnacho <carlosg src gnome org>]

commit c657b757f2877201c81cd092e942a0d35d15d741
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Mar 27 11:12:23 2021 +0100

    tracker-miner-fs: Fall back if no modification date is found
    
    There are paths in GIO (mainly EACCES errors during stat) that we
    may get returned no error, but a GFileInfo that does not contain
    all the requested information. Cases that may trigger this are:
    
      - Odd permission patterns. I was able to reproduce with a
        directory from another user with 744 permissions, stat would
        then cause EACCES with the directory contents.
      - Other kernel reasons to deny access (SELinux, AppArmor, etc).
    
    This used not to be a problem, as only modification/access times
    missing used to be relevant to us, and we dealt with them as int64_t
    so we silently dealt with the returned 0, thus we set those times
    as being the "epoch". Now we try to get a GDateTime, and get a NULL
    pointer instead, causing crashes in its manipulation.
    
    As we need files to have a modification time for our comparisons
    during crawling, make these files have again a fictional date set
    in the epoch to avoid the crash and make the machinery work with
    these files.

 src/miners/fs/tracker-miner-files.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/src/miners/fs/tracker-miner-files.c b/src/miners/fs/tracker-miner-files.c
index 3c04f41db..1fda00de7 100644
--- a/src/miners/fs/tracker-miner-files.c
+++ b/src/miners/fs/tracker-miner-files.c
@@ -2137,7 +2137,10 @@ process_file_cb (GObject      *object,
        data->mime_type = g_strdup (mime_type);
        is_directory = (g_file_info_get_file_type (file_info) == G_FILE_TYPE_DIRECTORY ?
                        TRUE : FALSE);
+
        modified = g_file_info_get_modification_date_time (file_info);
+       if (!modified)
+               modified = g_date_time_new_from_unix_utc (0);
 
        if (!is_directory) {
                /* In case of update: delete all information elements for the given data object
@@ -2320,8 +2323,11 @@ process_file_attributes_cb (GObject      *object,
        uri = g_file_get_uri (file);
        resource = tracker_resource_new (uri);
 
-       /* Update nfo:fileLastModified */
        modified = g_file_info_get_modification_date_time (file_info);
+       if (!modified)
+               modified = g_date_time_new_from_unix_utc (0);
+
+       /* Update nfo:fileLastModified */
        time_str = g_date_time_format_iso8601 (modified);
        tracker_resource_set_string (resource, "nfo:fileLastModified", time_str);
        g_date_time_unref (modified);