[perl #99984] Incorrect errmsg with our $::é

Having PL_parser->error_count set to non-zero when utf8_heavy.pl tries
to do() one of its swashes results in ‘Compilation error’ being placed
in $@ during the do, even if it was successful.  This patch sets the
error_count to 0 before calling SWASHNEW, to prevent that.  It uses
SAVEI8, to make sure it is restored on scope exit.

2 files changed, 10 insertions, 1 deletions

diff --git a/t/uni/lex_utf8.t b/t/uni/lex_utf8.t
index e080245d6e..368185f130 100644
--- a/t/uni/lex_utf8.t
+++ b/t/uni/lex_utf8.t
@@ -12,7 +12,7 @@ BEGIN {
 
 use strict;
 
-plan (tests => 10);
+plan (tests => 11);
 use charnames ':full';
 
 use utf8;
@@ -40,6 +40,13 @@ do {
 	is((join "", unpack("C*", $uname_last)), "98" . "198" . "129" . "194" . "181", 'b . char above 0x100 . \N{U+00B5}');
 	is((join "", unpack("C*", $octal_first)), "99" . "195" . "191" . "196" . "134", 'c . \377 . char above 0x100');
 	is((join "", unpack("C*", $octal_last)), "99" . "196" . "134" . "195" . "191", 'c . char above 0x100 . \377');
+};
+
+{
+    local $SIG{__WARN__} = sub {};
+    eval "our $::\xe9; $\xe9";
+    unlike $@, qr/utf8_heavy/,
+	'No utf8_heavy errors with our() syntax errors';
 }
 __END__
 
diff --git a/utf8.c b/utf8.c
index 4bab3a9b84..003e3fcadd 100644
--- a/utf8.c
+++ b/utf8.c
@@ -2050,6 +2050,8 @@ Perl_swash_init(pTHX_ const char* pkg, const char* name, SV *listsv, I32 minbits
     ENTER;
     SAVEHINTS();
     save_re_context();
+    if (PL_parser && PL_parser->error_count)
+	SAVEI8(PL_parser->error_count), PL_parser->error_count = 0;
     method = gv_fetchmeth(stash, "SWASHNEW", 8, -1);
     if (!method) {	/* demand load utf8 */
 	ENTER;