Fix issues around .pgpass file.
This commit fixes the following two issues around .pgpass file.
(1) If the length of a line in .pgpass file was larger than 319B,
libpq silently treated each 319B in the line as a separate
setting line.
(2) The document explains that a line beginning with # is treated
as a comment in .pgpass. But there was no code doing such
special handling. Whether a line begins with # or not, libpq
just checked that the first token in the line match with the host.
For (1), this commit makes libpq warn if the length of a line
is larger than 319B, and throw away the remaining part beginning
from 320B position.
For (2), this commit changes libpq so that it treats any lines
beginning with # as comments.
Author: Fujii Masao
Reviewed-by: Hamid Akhtar
Discussion: https://postgr.es/m/
c0f0c01c-fa74-9749-2084-
b73882fd5465@oss.nttdata.com