Allow the \$ proto to accept any scalar lvalue [perl #91846]

This makes the \$ prototype’s parsing the same as the second argument
to read(), making it possible to create a custom myread() function
that has the same syntax.

This is handled in two places in the prototype-parsing code, to avoid
calling scalar() on the op if another character in \[...] will accept
it.  I don’t know what the consequences of that would be.  So it calls
Perl_op_lvalue_flags in the $ case only if it is not inside brackets.
Then in the ] case it checks to see whether there was a $.

OP_READ, not OP_ENTERSUB, is passed as the type to
Perl_op_lvalue_flags, since OP_ENTERSUB would allow sub foo(\$) to
accept an array as an argument.  OP_RECV and OP_SYSREAD would have
worked, too.

1 files changed, 6 insertions, 1 deletions

diff --git a/t/comp/proto.t b/t/comp/proto.t
index a982f6aff2..50aebef875 100644
--- a/t/comp/proto.t
+++ b/t/comp/proto.t
@@ -18,7 +18,7 @@ BEGIN {
 # strict
 use strict;
 
-print "1..171\n";
+print "1..174\n";
 
 my $i = 1;
 
@@ -545,6 +545,9 @@ sub sreftest (\$$) {
     sreftest($helem{$i}, $i++);
     sreftest $aelem[0], $i++;
     sreftest sub { [0] }->()[0], $i++;
+    sreftest my $a = 'quidgley', $i++;
+    print "not " if eval 'return 1; sreftest(3+4)';
+    print "ok ", $i++, ' - \$ with invalid argument', "\n";
 }
 
 # test single term
@@ -599,6 +602,8 @@ for my $p ( "", qw{ () ($) ($@) ($%) ($;$) (&) (&\@) (&@) (%) (\%) (\@) } ) {
 
     print "not " unless myref($myvar)   =~ /^SCALAR\(/;
     print "ok ", $i++, "\n";
+    print "not " unless myref($myvar=7) =~ /^SCALAR\(/;
+    print "ok ", $i++, "\n";
     print "not " unless myref(@myarray) =~ /^ARRAY\(/;
     print "ok ", $i++, "\n";
     print "not " unless myref(%myhash)  =~ /^HASH\(/;