for my ($x) ...: fix handling of degenerate 1-var

The new

    for my ($x,$y,...) (...) { ... }

syntax has a couple of problems in the degenerate case of a single
variable:

    for my ($x) (...) { ... }

First, the loop variable is marked as lexical, but not as a variable
to be introduced. So it behaves roughly as if written like:

    { my $x; for $x (...) { ... } }

I can't think of any user-visible runtime change in behaviour this bug
causes, so I haven't included a test for it.

Second, it was being incorrectly deparsed as

    for $x (...) { ... }

(i.e. without the 'my').

This commit fixes both of these issues.

The basic problem is that the parser, in the case of multiple vars,
passes a list subtree of PADSVs as the 'sv' argument of Perl_newFOROP,
but in the case of a single var, passes a single PADSV op instead.
This single PADSV doesn't have the LVINTRO flag set, so is
indistinguishable from plain

    my $x; for $x ....

This commit makes the parser set the OPf_PARENS flag on the lone PADSV
to signal to newFOROP() that it's a degenerate 1-var list, and
newFOROP() sets the OPf_PARENS flag on the ENTERITER op to signal to the
deparser that this is "for my (...)" syntax, even if it only has a
single var.

1 files changed, 8 insertions, 8 deletions

diff --git a/ext/B/t/optree_for.t b/ext/B/t/optree_for.t
index a72324cfaf..415a1492c8 100644
--- a/ext/B/t/optree_for.t
+++ b/ext/B/t/optree_for.t
@@ -194,7 +194,7 @@ checkOptree ( name      => 'for my ($var) (@a)',
 2  <0> pushmark sM
 3  <#> gv[*a] s
 4  <1> rv2av[t3] sKRM/1
-5  <{> enteriter(next->7 last->a redo->6)[$var:1474,1477] KS
+5  <{> enteriter(next->7 last->a redo->6)[$var:1474,1477] KPS/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v
@@ -207,7 +207,7 @@ EOT_EOT
 2  <0> pushmark sM
 3  <$> gv(*a) s
 4  <1> rv2av[t2] sKRM/1
-5  <{> enteriter(next->7 last->a redo->6)[$var:1474,1477] KS
+5  <{> enteriter(next->7 last->a redo->6)[$var:1474,1477] KPS/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v
@@ -225,7 +225,7 @@ checkOptree ( name      => 'for my ($var) (@lexical)',
 1  <;> nextstate(main 1466 optree_for.t:100) v
 2  <0> pushmark sM
 3  <0> padav[@lexical:FAKE::7] sRM
-4  <{> enteriter(next->6 last->9 redo->5)[$var:1481,1484] KS
+4  <{> enteriter(next->6 last->9 redo->5)[$var:1481,1484] KPS/LVINTRO
 7  <0> iter s
 8  <|> and(other->5) K/1
 5      <0> stub v
@@ -237,7 +237,7 @@ EOT_EOT
 1  <;> nextstate(main 424 optree_for.t:111) v:>,<,%
 2  <0> pushmark sM
 3  <0> padav[@lexical:FAKE::2] sRM
-4  <{> enteriter(next->6 last->9 redo->5)[$var:1481,1484] KS
+4  <{> enteriter(next->6 last->9 redo->5)[$var:1481,1484] KPS/LVINTRO
 7  <0> iter s
 8  <|> and(other->5) K/1
 5      <0> stub v
@@ -256,7 +256,7 @@ checkOptree ( name      => 'for my ($key, $value) (%h)',
 2  <0> pushmark sM
 3  <#> gv[*h] s
 4  <1> rv2hv[t4] lKM
-5  <{> enteriter(next->7 last->a redo->6)[$key:1488,1491; $value:1488,1491] K/LVINTRO
+5  <{> enteriter(next->7 last->a redo->6)[$key:1488,1491; $value:1488,1491] KP/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v
@@ -269,7 +269,7 @@ EOT_EOT
 2  <0> pushmark sM
 3  <$> gv(*h) s
 4  <1> rv2hv[t3] lKM
-5  <{> enteriter(next->7 last->a redo->6)[$key:1488,1491; $value:1488,1491] K/LVINTRO
+5  <{> enteriter(next->7 last->a redo->6)[$key:1488,1491; $value:1488,1491] KP/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v
@@ -288,7 +288,7 @@ checkOptree ( name      => 'for my ($foo, $bar, $baz) (@a)',
 2  <0> pushmark sM
 3  <#> gv[*a] s
 4  <1> rv2av[t5] sKRM/1
-5  <{> enteriter(next->7 last->a redo->6)[$foo:1495,1498; $bar:1495,1498; $baz:1495,1498] KS/LVINTRO
+5  <{> enteriter(next->7 last->a redo->6)[$foo:1495,1498; $bar:1495,1498; $baz:1495,1498] KPS/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v
@@ -301,7 +301,7 @@ EOT_EOT
 2  <0> pushmark sM
 3  <$> gv(*a) s
 4  <1> rv2av[t4] sKRM/1
-5  <{> enteriter(next->7 last->a redo->6)[$foo:1495,1498; $bar:1495,1498; $baz:1495,1498] KS/LVINTRO
+5  <{> enteriter(next->7 last->a redo->6)[$foo:1495,1498; $bar:1495,1498; $baz:1495,1498] KPS/LVINTRO
 8  <0> iter s
 9  <|> and(other->6) K/1
 6      <0> stub v