Em sex., 11 de jun. de 2021 às 19:49, Andres Freund <andres@anarazel.de> escreveu:
Hi,
On 2020-04-23 14:36:15 +0900, Kyotaro Horiguchi wrote: > At Thu, 23 Apr 2020 01:21:21 -0300, Ranier Vilela <ranier.vf@gmail.com> wrote in > > Em qua., 22 de abr. de 2020 às 23:27, Kyotaro Horiguchi < > > horikyota.ntt@gmail.com> escreveu: > > > > > > - strncpy(sqlca->sqlerrm.sqlerrmc, message, > > > sizeof(sqlca->sqlerrm.sqlerrmc)); > > > - sqlca->sqlerrm.sqlerrmc[sizeof(sqlca->sqlerrm.sqlerrmc) - 1] = 0; > > > + sqlca->sqlerrm.sqlerrmc[sizeof(sqlca->sqlerrm.sqlerrmc) - 1] = > > > '\0'; > > > + strncpy(sqlca->sqlerrm.sqlerrmc, message, > > > sizeof(sqlca->sqlerrm.sqlerrmc) - 1); > > > > > > The existing strncpy then terminating by NUL works fine. I don't think > > > there's any point in doing the reverse way. Actually > > > sizeof(sqlca->sqlerrm.sqlerrmc) - 1 is enough for the length but the > > > existing code is not necessarily a bug. > > > > > Without understanding then, why Coveriy claims bug here. > > Well, handling non-terminated strings with str* functions are a sign > of bug in most cases. Coverity is very useful but false positives are > annoying. I wonder what if we attach Coverity annotations to such > codes.
It might be worth doing something about this, for other reasons. We have disabled -Wstringop-truncation in 716585235b1. But I've enabled it in my debug build, because I find it useful. The only warning we're getting in non-optimized builds is
/home/andres/src/postgresql/src/interfaces/ecpg/ecpglib/misc.c: In function ‘ECPGset_var’: /home/andres/src/postgresql/src/interfaces/ecpg/ecpglib/misc.c:565:17: warning: ‘strncpy’ output truncated before terminating nul copying 5 bytes from a string of the same length [-Wstringop-truncation] 565 | strncpy(sqlca->sqlstate, "YE001", sizeof(sqlca->sqlstate)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
