[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, 5 insertions, 1 deletions

diff --git a/t/op/bop.t b/t/op/bop.t
index 238d2727fa..0f28f79244 100644
--- a/t/op/bop.t
+++ b/t/op/bop.t
@@ -15,7 +15,7 @@ BEGIN {
 # If you find tests are failing, please try adding names to tests to track
 # down where the failure is, and supply your new names as a patch.
 # (Just-in-time test naming)
-plan tests => 171 + (10*13*2) + 4;
+plan tests => 171 + (10*13*2) + 5;
 
 # numerics
 ok ((0xdead & 0xbeef) == 0x9ead);
@@ -554,3 +554,7 @@ $strval = "x";
 eval { $obj |= "Q" };
 $strval = "z";
 is("$obj", "z", "|= doesn't break string overload");
+
+# [perl #29070]
+$^A .= new version ~$_ for "\xce", v205, "\xcc";
+is $^A, "123", '~v0 clears vstring magic on retval';