Flush PL_stashcache when assigning a file handle to a typeglob.

File handles take priority over stashes for method dispatch. Assigning a
file handle to a typeglob potentially creates a file handle where one did
not exist before. As PL_stashcache only contains entries for names which
unambiguously resolve to stashes, such a change may mean that PL_stashcache
now contains an invalid entry. As it's hard to work out exactly which entries
might be affected, simply flush the entire cache and let it rebuild itself.

1 files changed, 8 insertions, 0 deletions

diff --git a/sv.c b/sv.c
index bd8afb7bbe..2417e86730 100644
--- a/sv.c
+++ b/sv.c
@@ -3883,6 +3883,14 @@ S_glob_assign_ref(pTHX_ SV *const dstr, SV *const sstr)
 	    assert(mg);
 	    Perl_magic_clearisa(aTHX_ NULL, mg);
 	}
+        else if (stype == SVt_PVIO) {
+            DEBUG_o(Perl_deb(aTHX_ "glob_assign_ref clearing PL_stashcache\n"));
+            /* It's a cache. It will rebuild itself quite happily.
+               It's a lot of effort to work out exactly which key (or keys)
+               might be invalidated by the creation of the this file handle.
+            */
+            hv_clear(PL_stashcache);
+        }
 	break;
     }
     SvREFCNT_dec(dref);