here-doc in quotes in multiline s//.../e in eval

When <<END occurs on the last line of a quote-like operator inside a
string eval ("${\<<END}"), it peeks into the linestr buffer of the
parent lexing scope (quote-like operators start a new lexing scope
with the linestr buffer containing what is between the quotes) to find
the body of the here-doc.  It modifies that buffer, stealing however
much it needs.

It was not leaving things in the consistent state that s///e checks
for when it finishes parsing the replacement (to make sure s//}+{/
doesn’t ‘work’).  Specifically, it was not shrinking the parent buf-
fer, so when PL_bufend was reset in sublex_done to the end of the par-
ent buffer, it was pointing to the wrong spot.

1 files changed, 9 insertions, 1 deletions

diff --git a/t/base/lex.t b/t/base/lex.t
index d55b189bfa..559cc30021 100644
--- a/t/base/lex.t
+++ b/t/base/lex.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..58\n";
+print "1..59\n";
 
 $x = 'x';
 
@@ -280,3 +280,11 @@ ok 58 - heredoc after "" in s/// in eval
 END
 ';
 print $_ || "not ok 58\n";
+
+$_ = "";
+eval 's|(?:)|"${\<<\END}"
+ok 59 - heredoc in "" in multiline s///e in eval
+END
+|e
+';
+print $_ || "not ok 59\n";