xprintf, xprintf-posix, xprintf-gnu: Use *zprintf.
* lib/xprintf.h (xprintf, xvprintf, xfprintf, xvfprintf): Change return
type to off64_t. Move documentation from xprintf.c to here. Mention
EOVERFLOW as another possible error unrelated to file I/O.
* lib/xprintf.c (xprintf): Change return type to off64_t.
(xvprintf): Likewise. Use vzprintf.
(xfprintf): Change return type to off64_t.
(xvfprintf): Likewise. Use vfzprintf.
* modules/xprintf (Description): Mention also fprintf. Mention EOVERFLOW
as another possible error unrelated to file I/O.
(Depends-on): Add vzprintf, vfzprintf.
* modules/xprintf-posix (Description): Mention also fprintf. Mention
EOVERFLOW as another possible error unrelated to file I/O.
(Depends-on): Add vzprintf-posix, vfzprintf-posix. Remove vprintf-posix,
vfprintf-posix.
* modules/xprintf-gnu (Description): Mention also fprintf. Mention
EOVERFLOW as another possible error unrelated to file I/O.
(Depends-on): Add vzprintf-gnu, vfzprintf-gnu. Remove vprintf-gnu,
vfprintf-gnu.
* tests/test-xprintf-posix.c (RETTYPE): Change to off64_t.
* tests/test-xfprintf-posix.c (RETTYPE): Likewise.
* NEWS: Document the change.