From: Vincent Pit <vince@profvince.com>
Date: Tue, 10 Mar 2015 19:33:52 +0000 (-0300)
Subject: Simplify vmg_call_sv() so that ERRSV is no longer used as a lvalue
X-Git-Tag: rt101410~2
X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FVariable-Magic.git;a=commitdiff_plain;h=aae88f4cf6f2f32553f8cc29cb8f0792cb5cd910

Simplify vmg_call_sv() so that ERRSV is no longer used as a lvalue

It's less hackish and more resilient to core changes.
---

diff --git a/Magic.xs b/Magic.xs
index 9a07ac5..61bc9e0 100644
--- a/Magic.xs
+++ b/Magic.xs
@@ -285,8 +285,8 @@ STATIC I32 vmg_call_sv(pTHX_ SV *sv, I32 flags, int (*cleanup)(pTHX_ void *), vo
  SV *old_err = NULL;
 
  if (SvTRUE(ERRSV)) {
-  old_err = ERRSV;
-  ERRSV   = newSV(0);
+  old_err = newSVsv(ERRSV);
+  sv_setsv(ERRSV, &PL_sv_undef);
  }
 
  cxix     = (cxstack_ix < cxstack_max) ? (cxstack_ix + 1) : Perl_cxinc(aTHX);
@@ -299,11 +299,8 @@ STATIC I32 vmg_call_sv(pTHX_ SV *sv, I32 flags, int (*cleanup)(pTHX_ void *), vo
  cxstack[cxix] = saved_cx;
 
  if (SvTRUE(ERRSV)) {
-  if (old_err) {
-   sv_setsv(old_err, ERRSV);
-   SvREFCNT_dec(ERRSV);
-   ERRSV = old_err;
-  }
+  SvREFCNT_dec(old_err);
+
   if (IN_PERL_COMPILETIME) {
    if (!PL_in_eval) {
     if (PL_errors)
@@ -326,8 +323,8 @@ STATIC I32 vmg_call_sv(pTHX_ SV *sv, I32 flags, int (*cleanup)(pTHX_ void *), vo
   }
  } else {
   if (old_err) {
-   SvREFCNT_dec(ERRSV);
-   ERRSV = old_err;
+   sv_setsv(ERRSV, old_err);
+   SvREFCNT_dec(old_err);
   }
  }