Re: [libvirt] [PATCHv2 2/2] util: Don't fail virGetGroupIDByName when group not found

virGetGroupIDByName is documented as returning 1 if the groupname cannot be found. getgrnam_r is documented as returning: « 0 or ENOENT or ESRCH or EBADF or EPERM or ... The given name or gid was not found. » and that: « The formulation given above under "RETURN VALUE" is from POSIX.1-2001. It does not call "not found" an error, hence does not specify what value errno might have in this situation. But that makes it impossible to recognize errors. One might argue that according to POSIX errno should be left unchanged if an entry is not found. Experiments on various UNIX-like systems shows that lots of different values occur in this situation: 0, ENOENT, EBADF, ESRCH, EWOULDBLOCK, EPERM and probably others. » virGetGroupIDByName returns an error when the return value of getgrnam_r is non-0. However on my RHEL system, getgrnam_r returns ENOENT when the requested user cannot be found, which then causes virGetGroupID not to behave as documented (it returns an error instead of falling back to parsing the passed-in value as an gid). This commit makes virGetGroupIDByName only report an error when errno is set to one of the values in the posix description of getgrnam_r (which are the same as the ones described in the manpage on my system). --- src/util/util.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)