Make stacked -l work

Perl 5.10.0 introduced stacked filetest operators,

   -x -r $foo

being equivalent to

    -r $foo && -x _

That does not work with -l.  It was these suspicious lines in
Perl_my_lstat_flags that drew my attention to it:

>     else if (PL_laststype != OP_LSTAT
> 	    && (PL_op->op_private & OPpFT_STACKED) && ckWARN(WARN_IO))
> 	Perl_croak(aTHX_ no_prev_lstat);

That croak only happens when warnings are on.  Warnings are just
supposed to be warnings, unless the ‘user’ explicitly requests
fatal warnings.

$ perl -le 'print "foo", -l -e "miniperl"'
foo
$ perl -lwe 'print "foo", -l -e "miniperl"'
The stat preceding -l _ wasn't an lstat at -e line 1.

That it doesn’t die in the first example is a bug.

In fact, it’s using the return value of -e as a file name:

$ ln -s miniperl 1
$ ./miniperl -le 'print -l -e "miniperl"'
1

And, with warnings on, if the preceding stat *was* an lstat, it
falls back to the pre-stacked behaviour, just as it does when warn-
ings are off.

It’s meant to be equivalent to -e "miniperl" && -l _ (which is why the
error message above says ‘The stat preceding -l _’).

diff --git a/doio.c b/doio.c
index 838786e..f03db27 100644 (file)
--- a/doio.c
+++ b/doio.c
@@ -1342,9 +1342,11 @@ Perl_my_lstat_flags(pTHX_ const U32 flags)
        }
        return (PL_laststatval = -1);
     }
-    else if (PL_laststype != OP_LSTAT
-           && (PL_op->op_private & OPpFT_STACKED) && ckWARN(WARN_IO))
+    else if (PL_op->op_private & OPpFT_STACKED) {
+      if (PL_laststype != OP_LSTAT)
        Perl_croak(aTHX_ no_prev_lstat);
+      return PL_laststatval;
+    } 
 
     PL_laststype = OP_LSTAT;
     PL_statgv = NULL;

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 9304c49..020965b 100644 (file)
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -839,6 +839,13 @@ this was not the case for C<goto &CORE::sub>.  The CORE sub would end up
 running with the lexical hints of the subroutine it replaced, instead of
 that subroutine's caller.  This has been fixed.
 
+=item *
+
+Stacked C<-l> (followed immediately by other filetest operators) did not
+work previously; now it does.  It is only permitted when the rightmost
+filetest op has the special "_" handle for its argument and the most
+recent C<stat>/C<lstat> call was an C<lstat>.
+
 =back
 
 =head1 Known Problems

diff --git a/pp_sys.c b/pp_sys.c
index eb324df..0a3d3cb 100644 (file)
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -3214,6 +3214,7 @@ PP(pp_ftlink)
     I32 result;
 
     tryAMAGICftest_MG('l');
+    STACKED_FTEST_CHECK;
     result = my_lstat_flags(0);
     SPAGAIN;
 

diff --git a/t/op/filetest.t b/t/op/filetest.t
index 08380d1..3b09c2b 100644 (file)
--- a/t/op/filetest.t
+++ b/t/op/filetest.t
@@ -10,7 +10,7 @@ BEGIN {
 }
 
 use Config;
-plan(tests => 30 + 27*14);
+plan(tests => 33 + 27*14);
 
 ok( -d 'op' );
 ok( -f 'TEST' );
@@ -89,6 +89,29 @@ is( -f -s $tempfile, 0 );
 is( -s -f $tempfile, 0 );
 unlink_all $tempfile;
 
+# stacked -l
+eval { -l -e "TEST" };
+like $@, qr/^The stat preceding -l _ wasn't an lstat at /,
+  'stacked -l non-lstat error with warnings off';
+{
+ local $^W = 1;
+ eval { -l -e "TEST" };
+ like $@, qr/^The stat preceding -l _ wasn't an lstat at /,
+  'stacked -l non-lstat error with warnings on';
+}
+# Make sure -l is using the previous stat buffer, and not using the previ-
+# ous op’s return value as a file name.
+SKIP: {
+ use Perl::OSType 'os_type';
+ if (os_type ne 'Unix') { skip "Not Unix", 1 }
+ chomp(my $ln = `which ln`);
+ if ( ! -e $ln ) { skip "No ln"   , 1 }
+ lstat "TEST";
+ `ln -s TEST 1`;
+ ok ! -l -e _, 'stacked -l uses previous stat, not previous retval';
+ unlink 1;
+}
+
 # test that _ is a bareword after filetest operators
 
 -f 'TEST';