In the merge c51f85f882
the files row0trunc.cc and read0read.cc were not supposed
to be changed in MariaDB 10.3.
The row0trunc.cc code that was changed in MariaDB 10.2
commit 3db94d2403 does not exist,
because it was removed earlier in 10.3
commit 5a1868b58d.
When it comes to read0read.cc, as explained in the 10.2
commit e0271a7b43
the code had been moved to trx0sys.h in 10.3. In
10.3 commit 380069c235
appproriate mutex protection was added to checking the
transaction system state. The assertion expression was
properly updated in the earlier merge
commit acf6f92aa9.
5c93509aad