Message successfully thawed, (or at least * its frozen count has successfully been reduced by 1).
An attempt was made to thaw * an unfrozen message. That is, there have been an unbalanced * number of calls to notmuch_message_freeze and * notmuch_message_thaw.
Thaw the current 'message', synchronizing any changes that may have occurred while 'message' was frozen into the notmuch database.
See notmuch_message_freeze for an example of how to use this function to safely provide tag changes.
Multiple calls to freeze/thaw are valid and these calls with "stack". That is there must be as many calls to thaw as to freeze before a message is actually thawed.
Return value: