BUG: realloc(p,0) is not conforming to C99/C11/C17/POSIX.1-2008

[Paul Eggert]

On 2024-10-28 09:47, Maciej W. Rozycki wrote:
>   A new paragraph begins saying what happens in one specific case:

The RETURN VALUE section gives two possibilities at the top level. The 
first is "Upon successful completion, ..."; the second is "If there is 
not enough available memory, ...". The specific case you mention, which 
lists as an option "A null pointer shall be returned", appears under the 
"Upon successful completion" possibility. This case is successful 
completion because the initial "Upon successful completion" sentence 
explicitly lists returning a null pointer as being successful.

Under the reading you gave, the RETURN VALUE section would jump back and 
forth and back and forth between describing successful and unsuccessful 
completion, with no hint to the reader as to which behavior is intended 
to be successful and which is not, and with one of the isolated 
unsuccessful-completion behaviors just happening to not apply to glibc. 
I don't find such a reading plausible: other RETURN VALUE sections 
consistently list successful completion behaviors first, then 
unsuccessful ones, and I see no reason why this RETURN VALUE section 
would differ from the general pattern.

>  Also who does this certification?  The Austin Group or someone else?

It's the Open Group; see <https://posix.opengroup.org/>.