[perl #77384] Passing a ref to warn doesn't append file and line

This commit makes pp_warn stringify the warning if there is no
$SIG{__WARN__} handler. See the RT ticket for the discussion.

1 files changed, 3 insertions, 1 deletions

diff --git a/pp_sys.c b/pp_sys.c
index 73a5c8ab55..30a2645459 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -449,7 +449,9 @@ PP(pp_warn)
     else {
 	exsv = newSVpvs_flags("Warning: something's wrong", SVs_TEMP);
     }
-    warn_sv(exsv);
+    if (SvROK(exsv) && !PL_warnhook)
+	 Perl_warn(aTHX_ "%"SVf, SVfARG(exsv));
+    else warn_sv(exsv);
     RETSETYES;
 }