Document: N1748
Date: 2013-08-30
Author: Douglas Walls
Subject: Suggested Technical Corregendum for DR 429

The original question asked in DR 429 was

  The runtime-constraint violation here can be caused by a null "s"
  pointer.  Should we discard the next input line even if (s == NULL) ?

When I wrote DR 429, I had not taken footnote 404) into account.

404) The gets_s function, unlike the historical gets function, makes it a runtime-constraint violation for
a line of input to overflow the buffer to store it. Unlike the fgets function, gets_s maintains a
one-to-one relationship between input lines and successful calls to gets_s. Programs that use gets
expect such a relationship.

I now believe the answer to the question I posed in DR 429 is yes.

The other minor issue pointed out in the DR is that that s[0] cannot be
set to the null character when s==NULL.  The following correction is offered.

Suggested Technical Corrigendum for DR 429

Annex K., replace paragraph 3 with the following:

If there is a runtime-constraint violation, characters are read and discarded from
stdin until a new-line character is read, or end-of-file or a read error occurs, and
if s is not a null pointer s[0] is set to the null character.