Re: Failure with make check-world for pgtypeslib/dt_test2 with HEAD on OSX

Michael Paquier <michael.paquier@gmail.com> writes:
> Hm... I have tried changing the system locales (to en_US for example) and
> time format but I can still trigger the issue all the time. I'll try to
> have a closer look.. It looks like this test does not like some settings at
> the OS level.

I eventually realized that the critical difference was you'd added
"CFLAGS=" to the configure call.  On this platform that has the net
effect of removing -O2 from the compiler flags, and apparently that
shifts around the stack layout enough to expose the clobber.

The fix is simple enough: ecpg's version of ParseDateTime is failing
to check for overrun of the field[] array until *after* it's already
clobbered the stack:

*** a/src/interfaces/ecpg/pgtypeslib/dt_common.c
--- b/src/interfaces/ecpg/pgtypeslib/dt_common.c
*************** ParseDateTime(char *timestr, char *lowst
*** 1695,1703 ****   while (*(*endstr) != '\0')   {       /* Record start of current field */
-       field[nf] = lp;       if (nf >= MAXDATEFIELDS)           return -1;        /* leading digit? then date or time
*/      if (isdigit((unsigned char) *(*endstr)))
 
--- 1695,1703 ----   while (*(*endstr) != '\0')   {       /* Record start of current field */       if (nf >=
MAXDATEFIELDS)          return -1;
 
+       field[nf] = lp;        /* leading digit? then date or time */       if (isdigit((unsigned char) *(*endstr)))

Kind of astonishing that nobody else has reported this, given that
there's been a regression test specifically meant to catch such a
problem since 4318dae.  The stack layout in PGTYPESdate_from_asc
must happen to avoid the issue on practically all platforms.
        regards, tom lane