Finish fixing here-docs in re-evals

This commit fixes here-docs in single-line re-evals in files (as
opposed to evals) and here-docs in single-line quote-like operators
inside re-evals.

In both cases, the here-doc parser has to look into an outer
lexing scope to find the here-doc body.  And in both cases it
was stomping on PL_linestr (the current line buffer) while
PL_sublex_info.re_eval_start was pointing to an offset in that buffer.
(re_eval_start is used to construct the string to include in the
regexp’s stringification once the lexer reaches the end of the
re-eval.)

Fixing this entails moving re_eval_start and re_eval_str to
PL_parser->lex_shared, making the pre-localised values visible.
This is so that the code that peeks into an outer linestr buffer to
steal the here-doc body can set up re_eval_str in the right scope.
(re_eval_str is used to store the re-eval text when the here-
oc parser has no choice but to modify linestr; see also commit
db4442662555874019.)

It also entails making the stream-based parser (i.e., that reads from
an input stream) leave PL_linestr alone, instead of clobbering it and
then reconstructing part of it afterwards.

1 files changed, 13 insertions, 1 deletions

diff --git a/t/base/lex.t b/t/base/lex.t
index 4c4981d94d..9868d4cf78 100644
--- a/t/base/lex.t
+++ b/t/base/lex.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..66\n";
+print "1..68\n";
 
 $x = 'x';
 
@@ -326,3 +326,15 @@ END
 
 eval 'print qq ;ok 66 - eval ending with semicolon\n;'
   or print "not ok 66 - eval ending with semicolon\n";
+
+print "not " unless qr/(?{<<END})/ eq '(?^:(?{<<END}))';
+foo
+END
+print "ok 67 - here-doc in single-line re-eval\n";
+
+$_ = qr/(?{"${<<END}"
+foo
+END
+})/;
+print "not " unless /foo/;
+print "ok 68 - here-doc in quotes in multiline re-eval\n";