Remove the tokeniser hack that prevents compile-time vivification of %stash::

This was put in to ensure that defined %stash:: continued to return false after
the implementation of hashes was changed, such that stashes were always defined.
defined %stash:: is deprecated.

This reverts the tokeniser changes of adc51b978ed1b2e9d4512c9bfa80386ac917d05a,
76138434928a968a390c791aec92e5f00017d01d,
d6069db2e52f58ef65bf59f2fd453604270d2205 and part of
9bde8eb087a2c05d4c8b0394a59d28a09fe5f529, and updates the tests added with those
commits to reflect the restored (but as yet unreleased) behaviour.

I don't think that this should be merged to blead until after 5.12.0 ships,
with the enabled deprecation warnings on defined %hash, as it changes subtle
behaviour that all current released stable perls accept without warning.

1 files changed, 4 insertions, 22 deletions

diff --git a/toke.c b/toke.c
index eac007e2da..dbac16f2c5 100644
--- a/toke.c
+++ b/toke.c
@@ -8052,28 +8052,10 @@ S_pending_ident(pTHX)
     pl_yylval.opval = (OP*)newSVOP(OP_CONST, 0, newSVpvn(PL_tokenbuf + 1,
 						      tokenbuf_len - 1));
     pl_yylval.opval->op_private = OPpCONST_ENTERED;
-    gv_fetchpvn_flags(
-	    PL_tokenbuf + 1, tokenbuf_len - 1,
-	    /* If the identifier refers to a stash, don't autovivify it.
-	     * Change 24660 had the side effect of causing symbol table
-	     * hashes to always be defined, even if they were freshly
-	     * created and the only reference in the entire program was
-	     * the single statement with the defined %foo::bar:: test.
-	     * It appears that all code in the wild doing this actually
-	     * wants to know whether sub-packages have been loaded, so
-	     * by avoiding auto-vivifying symbol tables, we ensure that
-	     * defined %foo::bar:: continues to be false, and the existing
-	     * tests still give the expected answers, even though what
-	     * they're actually testing has now changed subtly.
-	     */
-	    (*PL_tokenbuf == '%'
-	     && *(d = PL_tokenbuf + tokenbuf_len - 1) == ':'
-	     && d[-1] == ':'
-	     ? 0
-	     : PL_in_eval ? (GV_ADDMULTI | GV_ADDINEVAL) : GV_ADD),
-	    ((PL_tokenbuf[0] == '$') ? SVt_PV
-	     : (PL_tokenbuf[0] == '@') ? SVt_PVAV
-	     : SVt_PVHV));
+    gv_fetchpv(PL_tokenbuf+1, PL_in_eval ? (GV_ADDMULTI | GV_ADDINEVAL) : TRUE,
+               ((PL_tokenbuf[0] == '$') ? SVt_PV
+                : (PL_tokenbuf[0] == '@') ? SVt_PVAV
+                : SVt_PVHV));
     return WORD;
 }