diff options
author | Nicholas Clark <nick@ccl4.org> | 2011-07-01 09:28:20 +0200 |
---|---|---|
committer | Nicholas Clark <nick@ccl4.org> | 2011-07-01 09:28:20 +0200 |
commit | 36099d0a4368321504753a389cadaa15cc1cae23 (patch) | |
tree | 8318b725daafbdda4d1cd146ab6118617bf8a3f6 | |
parent | 637174112f90e2e782037f7c706f86617e7df263 (diff) | |
download | perl-36099d0a4368321504753a389cadaa15cc1cae23.tar.gz |
The test for #76474 should open file descriptor 0, not 1.
The original bug report states
if we try to dup STDIN in a child process by using it's file descriptor
but has code to dup 1, not 0:
perl -MIPC::Open3 -wle 'open3("<&1", my $out, undef, $^X)'
Change the above code to "<&0" and the same bug is demonstrated, and fixed by
the relevant change.
However, trying to open descriptor 1 for input causes subtle portability
problems, which conceal the actual bug we're attempting to test. On most
platforms the terminal is read write, and a command tested on the command line
actually has file descriptor 1 read/write (and probably file descriptor 0 also)
When the output is being piped, for example in a test checking the output,
descriptor 1 is (likely to be) write only. PerlIO is quite happy to *open* a
such a numeric file descriptor for reading, and will only generate an error if
an actual read is attempted (which this test does not). stdio (on several
platforms tested) fails the *open* in the same scenario. Hence whether this
*test* passed or failed depended on the IO system used, which is actually not
what we want to test.
Original test added in a0ed8b7b5f7f6d6f, fix added in fb9b5b31d8a62644.
-rw-r--r-- | ext/IPC-Open3/t/fd.t | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/ext/IPC-Open3/t/fd.t b/ext/IPC-Open3/t/fd.t index 354ebd1aa9..4e2742714d 100644 --- a/ext/IPC-Open3/t/fd.t +++ b/ext/IPC-Open3/t/fd.t @@ -1,10 +1,6 @@ #!./perl BEGIN { - if (!PerlIO::Layer->find('perlio') || $ENV{PERLIO} eq 'stdio') { - print "1..0 # Skip: not perlio\n"; - exit 0; - } if ($^O eq 'VMS') { print "1..0 # Skip: needs porting, perhaps imitating Win32 mechanisms\n"; exit 0; @@ -20,7 +16,7 @@ plan 3; { my $stderr = runperl( switches => ['-MIPC::Open3', '-w'], - prog => 'open STDIN, q _Makefile_ or die $!; open3(q _<&1_, my $out, undef, $ENV{PERLEXE}, q _-e0_)', + prog => 'open STDIN, q _Makefile_ or die $!; open3(q _<&0_, my $out, undef, $ENV{PERLEXE}, q _-e0_)', stderr => 1, ); |