New export errors with TL19

[Guenter Milde]

On 2019-12-12, Jürgen Spitzmüller wrote:

> [-- Type: text/plain, Encoding: quoted-printable --]

> Am Donnerstag, den 12.12.2019, 12:57 +0100 schrieb Kornel Benko:
>> Yes, this works here too.

> Will you fixup the text document?

In this case, please create also a minimal example of the failing
document in the "dedicated latex export tests" directory (we should not
expect users to add such preamble code to get working documents).

Günter