Issue discovered handling T143580:
```name=Terbium
$ mwscript namespaceDupes.php azwiktionary --fix --merge
id=7935 ns=0 dbk=Vikilüğət:Kənd_meydanı => Vikilüğət:Kənd_meydanı (merge)
[322d0f64aea67bd63616c5d9] [no req] DBUnexpectedError from line 2753 of /srv/mediawiki/php-1.28.0-wmf.15/includes/db/Database.php: DatabaseBase::{closure}: Flushing an explicit transaction, getting out of sync!
Backtrace:
#0 /srv/mediawiki/php-1.28.0-wmf.15/includes/db/Database.php(3305): DatabaseBase->commit(string, string)
#1 [internal function]: DatabaseBase->{closure}()
#2 /srv/mediawiki/php-1.28.0-wmf.15/includes/libs/ScopedCallback.php(74): call_user_func_array(Closure, array)
#3 [internal function]: ScopedCallback->__destruct()
#4 [internal function]: DatabaseBase->getScopedLockAndFlush(string, string, integer)
#5 /srv/mediawiki/php-1.28.0-wmf.15/includes/db/DBConnRef.php(39): call_user_func_array(array, array)
#6 /srv/mediawiki/php-1.28.0-wmf.15/includes/db/DBConnRef.php(517): DBConnRef->__call(string, array)
#7 /srv/mediawiki/php-1.28.0-wmf.15/includes/deferred/LinksUpdate.php(178): DBConnRef->getScopedLockAndFlush(string, string, integer)
#8 /srv/mediawiki/php-1.28.0-wmf.15/includes/deferred/LinksDeletionUpdate.php(62): LinksUpdate::acquirePageLock(DBConnRef, integer)
#9 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/namespaceDupes.php(609): LinksDeletionUpdate->doUpdate()
#10 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/namespaceDupes.php(316): NamespaceConflictChecker->mergePage(stdClass, Title)
#11 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/namespaceDupes.php(176): NamespaceConflictChecker->checkNamespace(integer, string, array)
#12 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/namespaceDupes.php(86): NamespaceConflictChecker->checkAll(array)
#13 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/doMaintenance.php(106): NamespaceConflictChecker->execute()
#14 /srv/mediawiki/php-1.28.0-wmf.15/maintenance/namespaceDupes.php(617): require_once(string)
#15 /srv/mediawiki/multiversion/MWScript.php(97): require_once(string)
#16 {main}
```