Use the same logic for getgrgid_r, getpwnam_r and getpwuid_r
as for getgrnam_r in #75696

Closes GH-5740.

Make sure we don't use zresource after the stream has been destroyed.

Even if the length of a maker note does not match our expectations
(either because the maker note is corrupted, or because our
expectations do not quite match reality), there is no need to let
parsing fail; we can still go on parsing the other meta information.

We have to loop over all image pixels to avoid the black border.  This
is also done in external libgd in `_gdScaleOneAxis` and `_gdScalePass`.

The `timercmp()` manpage[1] points out that some systems have a broken
implementation which does not support `>=`.  This is definitely the
case for the Windows SDK, which only supports `<` and `>`.

[1] <https://linux.die.net/man/3/timercmp>

While unencrypted connections ignore negative timeouts, SSL/TLS
connections did not special case that, and so always failed due to
timeout.

If the current character is a line break character, it cannot be a tab
or space character, so we would always fail with an invalid sequence
error.  Obviously, these `scan_stat == 4` conditions are meant to be
exclusive.

Furthermore, if `in_pp == NULL || in_left_p == NULL` is true, we hit a
segfault if we are not returning right away.  Obviously, the additional
constraints don't make sense, so we remove them.