On Sun, Oct 22, 2017 at 2:58 AM, Junio C Hamano <gitster@xxxxxxxxx> wrote:
> Christian Couder <christian.couder@xxxxxxxxx> writes:
>
>> To make it possible in a following commit to move packet
>> reading and writing functions into a Packet.pm module,
>> let's refactor these functions, so they don't handle
>> printing debug output and exiting.
>>
>> Signed-off-by: Christian Couder <chriscool@xxxxxxxxxxxxx>
>> ---
>> t/t0021/rot13-filter.pl | 12 ++++++++----
>> 1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
>> index ad685d92f8..e4495a52f3 100644
>> --- a/t/t0021/rot13-filter.pl
>> +++ b/t/t0021/rot13-filter.pl
>> @@ -60,8 +60,7 @@ sub packet_bin_read {
>> my $bytes_read = read STDIN, $buffer, 4;
>> if ( $bytes_read == 0 ) {
>> # EOF - Git stopped talking to us!
>> - print $debug "STOP\n";
>> - exit();
>> + return ( -1, "" );
>> }
>> elsif ( $bytes_read != 4 ) {
>> die "invalid packet: '$buffer'";
>> @@ -85,7 +84,7 @@ sub packet_bin_read {
>>
>> sub packet_txt_read {
>> my ( $res, $buf ) = packet_bin_read();
>> - unless ( $buf eq '' or $buf =~ s/\n$// ) {
>> + unless ( $res == -1 or $buf eq '' or $buf =~ s/\n$// ) {
>> die "A non-binary line MUST be terminated by an LF.";
>> }
>> return ( $res, $buf );
>> @@ -131,7 +130,12 @@ print $debug "init handshake complete\n";
>> $debug->flush();
>>
>> while (1) {
>> - my ( $command ) = packet_txt_read() =~ /^command=(.+)$/;
>> + my ( $res, $command ) = packet_txt_read();
>> + if ( $res == -1 ) {
>> + print $debug "STOP\n";
>> + exit();
>> + }
>> + $command =~ s/^command=//;
>> print $debug "IN: $command";
>> $debug->flush();
>
> This was not an issue in the old code which died upon unexpected EOF
> inside the lowest-level helper packet_bin_read(), but now you have
> one call to packet_bin_read() and many calls to packet_txt_read()
> whose return value is not checked for this new condition you are
> allowing packet_bin_read() to return. This step taken alone is a
> regression---let's see how the remainder of the series updates the
> callers to compensate.
Yeah, in the new version I will send really soon now, I have made a
number of changes to check the return value for the EOF condition.
> I initially thought that it may be more Perl-ish to return undef or
> string instead of returning a 2-element list, but this code needs to
> distinguish three conditions (i.e. a normal string that is 0 or more
> bytes long, a flush, and an EOF), so that is not sufficient. Perl
> experts on the list still may be able to suggest a better way than
> the current one to do so, but that is outside the scope of this
> refactoring.
Yeah I can't think of a better way either.
Thanks.
