[perl #29070] Add vstring set-magic

Some operators, like pp_complement, assign their argument to TARG
(which copies vstring magic), modify it in place, and then call set-
magic.  That’s supposed to work, but vstring magic was remaining as it
was, such that ~v7 would still be treated as "v7" by vstring-aware
code, even though the resulting string is not "\7".

This commit adds vstring set-magic that checks to see whether the pv
still matches the vstring.  It cannot simply free the vstring magic,
as that would prevent $x=v0 from working.

1 files changed, 1 insertions, 1 deletions

diff --git a/mg_raw.h b/mg_raw.h
index 7a45e6de0f..f4e174247b 100644
--- a/mg_raw.h
+++ b/mg_raw.h
@@ -74,7 +74,7 @@
       "/* taint 't' Taintedness */" },
     { 'U', "want_vtbl_uvar",
       "/* uvar 'U' Available for use by extensions */" },
-    { 'V', "magic_vtable_max | PERL_MAGIC_VALUE_MAGIC",
+    { 'V', "want_vtbl_vstring | PERL_MAGIC_VALUE_MAGIC",
       "/* vstring 'V' SV was vstring literal */" },
     { 'v', "want_vtbl_vec | PERL_MAGIC_VALUE_MAGIC",
       "/* vec 'v' vec() lvalue */" },