Followup to 088225f/[perl #88132]: packages ending with :

Commit 088225f was not sufficient to fix the regression. It still
exists for packages whose names end with a single colon.

I discovered this when trying to determine why RDF::Trine was crashing
with 5.14-to-be.

In trying to write tests for it, I ended up triggering the same crash
that RDF::Trine is having, but in a different way.

In the end, it was easier to fix about three or four bugs (depending
on how you count them), rather than try to fix only the regression
that #88132 deals with (isa caches not updating when packages ending
with colons are aliased), as they are all intertwined.

The changes are as follows:

Concerning the if (!(flags & ~GV_NOADD_MASK)...) statement in
gv_stashpvn: Normally, gv_fetchpvn_flags (which it calls and whose
retval is assigned to tmpgv) returns NULL if it has not been told
to add anything and if the gv requested looks like a stash gv (ends
with ::). If the number of colons is odd (foo:::), that code path is
bypassed, so gv_stashpvn returns a GV without a hash. So gv_stashpvn
tries to used that NULL hash and crashes. It should instead return
NULL, to be consistent with the two-colon case.

Blindly assigning a name to a stash does not work if the stash has
multiple effective names. A call to mro_package_moved is required as
well. So what gv_stashpvn was doing was insufficient.

The parts of the mro code that check for globs or stash elems that
contain stashes by looking for :: at the end of the name now take into
account that the name might consist of a single : instead.

1 files changed, 9 insertions, 1 deletions

diff --git a/gv.c b/gv.c
index 7741af36c9..d22a4398fb 100644
--- a/gv.c
+++ b/gv.c
@@ -959,8 +959,16 @@ Perl_gv_stashpvn(pTHX_ const char *name, U32 namelen, I32 flags)
     if (!tmpgv)
 	return NULL;
     stash = GvHV(tmpgv);
-    if (!HvNAME_get(stash))
+    if (!(flags & ~GV_NOADD_MASK) && !stash) return NULL;
+    if (!HvNAME_get(stash)) {
 	hv_name_set(stash, name, namelen, 0);
+	
+	/* FIXME: This is a repeat of logic in gv_fetchpvn_flags */
+	/* If the containing stash has multiple effective
+	   names, see that this one gets them, too. */
+	if (HvAUX(GvSTASH(tmpgv))->xhv_name_count)
+	    mro_package_moved(stash, NULL, tmpgv, 1);
+    }
     assert(stash);
     return stash;
 }