&CORE::caller()

This commit allows &CORE::caller to be called through references and
via ampersand syntax.  pp_caller is modified to take into account
two things:
1) pp_coreargs pushes a null on to the stack, since it has no other
   way to tell caller whether it has an argument.
2) The value coming from pp_coreargs (when not null) is off by
   one.  The OPpOFFYBONE flag was added in commit 93f0bc4935 for
   this purpose.

pp_coreargs is also modified, since it assumed till now that an
optional first argument was an implicit $_.

1 files changed, 2 insertions, 1 deletions

diff --git a/pp.c b/pp.c
index 04e4e4afd8..7cffe23aa2 100644
--- a/pp.c
+++ b/pp.c
@@ -6010,6 +6010,7 @@ PP(pp_coreargs)
 {
     dSP;
     int opnum = SvIOK(cSVOP_sv) ? (int)SvUV(cSVOP_sv) : 0;
+    int defgv = PL_opargs[opnum] & OA_DEFGV;
     AV * const at_ = GvAV(PL_defgv);
     SV **svp = AvARRAY(at_);
     I32 minargs = 0, maxargs = 0, numargs = AvFILLp(at_)+1, whicharg = 0;
@@ -6048,7 +6049,7 @@ PP(pp_coreargs)
     PUTBACK; /* The code below can die in various places. */
 
     oa = PL_opargs[opnum] >> OASHIFT;
-    if (!numargs) {
+    if (!numargs && defgv) {
 	PERL_SI * const oldsi = PL_curstackinfo;
 	I32 const oldcxix = oldsi->si_cxix;
 	CV *caller;