scope.* - revert and rework SAVECOPWARNINGS change

We can't put PL_compiling or PL_curcop on the save stack as we don't
have a way to ensure they cross threads properly. This showed up as a
win32 t/op/fork.t failure in the thread based fork emulation layer.

This adds a new save type SAVEt_CURCOP_WARNINGS and macro
SAVECURCOPWARNINGS() to complement SAVEt_COMPILER_WARNINGS and
SAVECOMPILEWARNINGS(). By simply hard coding where the pointers should
be restored to we side step the issue of which thread we are in.

Thanks to Graham Knop for help identifying that one of my commits was
responsible.

1 files changed, 1 insertions, 3 deletions

diff --git a/utf8.c b/utf8.c
index 26baff464b..7c35fb8c12 100644
--- a/utf8.c
+++ b/utf8.c
@@ -76,9 +76,7 @@ Perl__force_out_malformed_utf8_message(pTHX_
 
     PL_dowarn = G_WARN_ALL_ON|G_WARN_ON;
     if (PL_curcop) {
-        /* this is like SAVECOMPILEWARNINGS() except with PL_curcop rather
-         * than PL_compiling */
-        SAVECOPWARNINGS(PL_curcop);
+        SAVECURCOPWARNINGS();
         PL_curcop->cop_warnings = pWARN_ALL;
     }