If fgets succeeds, then the resulting char array is always
terminated by a '\0'. No need to keep extra space, therefore
sizeof(buf) is the correct argument.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

The terminating nul character ('\0') could be written outside the boundary of
the buffer which is used to read characters. If "sizeof(buffer)" characters
are read, the resulting value must not be used as index, because that's an off
by one.

Read sizeof(buffer)-1 bytes instead.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

This feature was originally removed as part of 52d19f9.