From 035146a3ca31411488f684bee10fdd30d32ba7c3 Mon Sep 17 00:00:00 2001
From: Father Chrysostomos <sprout@cpan.org>
Date: Tue, 6 Dec 2011 23:07:49 -0800
Subject: [PATCH] Deparse funny keys/values in hh properly
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Simply putting '...' or q(...) around a string is not sufficient to
quote it properly, allowing this sort of ‘fun’:

$ perl -l -MO=Deparse -e'BEGIN{$^H{"'\''.'\''"} = "um);\n    exit("}print'
BEGIN { $/ = "\n"; $\ = "\n"; }
sub BEGIN {
    $^H{q['.']} = "um);\n    exit(";
}
BEGIN {
    $^H{''.''} = q(um);
    exit();
}
print $_;
-e syntax OK

And B::Deparse already has a facility for quoting strings, so why
not use it?
---
 dist/B-Deparse/Deparse.pm  | 9 +++++++--
 dist/B-Deparse/t/deparse.t | 2 ++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/dist/B-Deparse/Deparse.pm b/dist/B-Deparse/Deparse.pm
index 24d17af..c7bdec4 100644
--- a/dist/B-Deparse/Deparse.pm
+++ b/dist/B-Deparse/Deparse.pm
@@ -1511,8 +1511,13 @@ sub declare_hinthash {
     for my $key (keys %$to) {
 	next if $ignored_hints{$key};
 	if (!exists $from->{$key} or $from->{$key} ne $to->{$key}) {
-	    push @decls, qq(\$^H{'$key'} = )
-	      . (defined $to->{$key} ? qq(q($to->{$key})) : 'undef')
+	    push @decls,
+		qq(\$^H{) . single_delim("q", "'", $key) . qq(} = )
+	      . (
+		   defined $to->{$key}
+			? single_delim("q", "'", $to->{$key})
+			: 'undef'
+		)
 	      . qq(;);
 	}
     }
diff --git a/dist/B-Deparse/t/deparse.t b/dist/B-Deparse/t/deparse.t
index 7b11ccf..d47498c 100644
--- a/dist/B-Deparse/t/deparse.t
+++ b/dist/B-Deparse/t/deparse.t
@@ -807,3 +807,5 @@ BEGIN { $^H{'foo'} = undef; }
  }
  print $_;
 }
+BEGIN { $^H{q[']} = '('; }
+print $_;
-- 
2.7.4