When running a procedure and pressing 'Rebuild Code', the script is re-written incorrectly (4237729)

When running a procedure and pressing 'Rebuild Code', the script is re-written incorrectly, which subsequently causes an 'ORA-06550' error when it is run.

Toad generated the following script to the procedure:
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DECLARE
P_TEST CHAR(12);
P_TEST2 NUMBER;

BEGIN
P_TEST := '000000123456';
P_TEST2 := ;

SCHEMA_NAME.PROCEDURE NAME ( P_TEST, P_TEST2 );
COMMIT;
END;
------------------------------------

When the procedure is run, the following error occurs:

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'ORA-06550: line 7, column 17:
PLS-00103: Encountered the symbol ";" when expecting one of the following:

( - + mod not null <an identifier>
<a double-quoted delimited-identifier> <a bind variable> avg count current exists max min prior sql stddev sum variance execute forall time timestamp interval date
<a string literal with character set specification>
<a number> <a single-quoted SQL string>'
------------------------------------

The symbol "null" was substituted for ";" to continue.

WORKAROUND:
Manually change the line as follows:
P_TEST2 := NULL; or P_TEST2 := 0;

STATUS:
Waiting for fix in a future release of Toad for Oracle