bad things happened with for $x (...) { *x = *y }

fix for [perl #21469]:
since the GP may be pulled from under us and freed, coredumps and strange
things can happen.

Fix this by storing a pointer to the GV in the loop block, rather than a
pointer to the GvSV slot. The ITHREADS variant already stores GV rather
than than &GvSV; extend this to non-threaded builds too.

Also, for both threaded and non-threaded, it used to push &GvSV on the
save stack. Fix this by introducing a new save type, SAVEt_GVSV.
This behaves similarly to SAVEt_SV, but without magic get/set.

This means that

    for $package_var (...)

is now close in behaviour to

    local $package_var = ...

(except for the magic bit).

1 files changed, 1 insertions, 0 deletions

diff --git a/scope.h b/scope.h
index 7df44b6471..6cef09162e 100644
--- a/scope.h
+++ b/scope.h
@@ -57,6 +57,7 @@
 #define SAVEt_ADELETE		46
 #define SAVEt_I32_SMALL		47
 #define SAVEt_INT_SMALL		48
+#define SAVEt_GVSV		49
 
 #define SAVEf_SETMAGIC		1
 #define SAVEf_KEEPOLDELEM	2