Re: [BUG] notmuch_message_tags_to_maildir_flags does not always invalidate filenames_list

[David Bremner <david@tethera.net>]

Eliza Velasquez <eliza@eliza.sh> writes:

> Hello notmuch,
>
> As the subject says, it seems like the filename cache for a message is
> not reliably invalidated when notmuch_message_tags_to_maildir_flags is
> called, causing the following series of function calls to behave
> unexpectedly.
>
> - notmuch_database_index_file
> - notmuch_message_get_filenames
> - notmuch_message_tags_to_maildir_flags
> - notmuch_message_get_filenames (stale list returned)
>
> According to the investigator [1], this happens about 10% of the time,
> but it's possible that this is just because there is some quirk in the
> client-side code causing it to trigger only sometimes.

that cache is supposed to be invalidated by calls to
_notmuch_message_add_filename and
_notmuch_message_remove_filename. There is one unchecked call to
_notmuch_message_add_term that looks a bit suspect. The obvious thing
that can go wrong is filename getting too long. Here is a patch to maybe
return better diagnostics in that case

diff --git a/lib/message.cc b/lib/message.cc
index 63b216b6..bebc5f6a 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -169,6 +169,7 @@ _notmuch_message_create_for_document (const void *talloc_owner,
 
     message->doc = doc;
     message->termpos = 0;
+    message->modified = FALSE;
 
     return message;
 }
@@ -937,6 +938,7 @@ _notmuch_message_add_filename (notmuch_message_t *message,
 {
     const char *relative, *directory;
     notmuch_status_t status;
+    notmuch_private_status_t private_status;
     void *local = talloc_new (message);
     char *direntry;
 
@@ -960,7 +962,11 @@ _notmuch_message_add_filename (notmuch_message_t *message,
 
     /* New file-direntry allows navigating to this message with
      * notmuch_directory_get_child_files() . */
-    _notmuch_message_add_term (message, "file-direntry", direntry);
+    private_status = _notmuch_message_add_term (message, "file-direntry", direntry);
+    status = COERCE_STATUS (private_status,
+                           "Unexpected error from _notmuch_message_add_term");
+    if (status)
+       return status;
 
     _notmuch_message_add_folder_terms (message, directory);
     _notmuch_message_add_path_terms (message, directory);

The other issue that might cause intermittent failures is uncaught
exceptions. We cleaned a bunch of those up a few years ago, but it looks
like we missed a few spots. Off hand I'm not sure what would be causing
such exceptions, but _notmuch_message_add_term and
_notmuch_message_remove_term should probably have the Xapian operations
wrapped in try / catch blocks.

It might be worth running the failing test under gdb to see if you can
spot exceptions.