Don’t leak pattern buffer when invalid flags croak

Normally if there is a syntax error yyerror just records it and pars-
ing continues anyway.  If there are too many syntax errors, it croaks.

It just happened that if it croaked when encountering invalid flags
for quote-like operators it would leak the buffer containing the pat-
tern (and the substitution for s///).

Since those are stored in the parser struct and are set to null when-
ever something else takes ownership of the SV, these struct members
will only ever be non-null in parser_free when they have leaked.  So
we can free them there.  (I.e., these slots have always been refer-
ence-counted, so treat them that way.)

1 files changed, 3 insertions, 1 deletions

diff --git a/t/op/svleak.t b/t/op/svleak.t
index ee646d7c8b..dfb1886091 100644
--- a/t/op/svleak.t
+++ b/t/op/svleak.t
@@ -15,7 +15,7 @@ BEGIN {
 
 use Config;
 
-plan tests => 50;
+plan tests => 52;
 
 # run some code N times. If the number of SVs at the end of loop N is
 # greater than (N-1)*delta at the end of loop 1, we've got a leak
@@ -195,6 +195,8 @@ eleak(2, 0, 'tr/9-0//');
 eleak(2, 0, 'tr/a-z-0//');
 eleak(2, 0, 'no warnings; nonexistent_function 33838',
         'bareword followed by number');
+eleak(2, 0, '//dd;'x20, '"too many errors" when parsing m// flags');
+eleak(2, 0, 's///dd;'x20, '"too many errors" when parsing s/// flags');
 
 # [perl #114764] Attributes leak scalars
 leak(2, 0, sub { eval 'my $x : shared' }, 'my $x :shared used to leak');