[perl #127351] add isaelem magic on *Foo::ISA = arrayref

[perl5.git] / pp_sort.c

diff --git a/pp_sort.c b/pp_sort.c
index 3203f4c..51742f6 100644 (file)
--- a/pp_sort.c
+++ b/pp_sort.c
@@ -1432,7 +1432,7 @@ Sort an array.  Here is an example:
 
     sortsv(AvARRAY(av), av_top_index(av)+1, Perl_sv_cmp_locale);
 
-Currently this always uses mergesort.  See sortsv_flags for a more
+Currently this always uses mergesort.  See C<L</sortsv_flags>> for a more
 flexible routine.
 
 =cut
@@ -1657,14 +1657,21 @@ PP(pp_sort)
                PL_secondgv = MUTABLE_GV(SvREFCNT_inc(
                    gv_fetchpvs("b", GV_ADD|GV_NOTQUAL, SVt_PV)
                ));
+                /* make sure the GP isn't removed out from under us for
+                 * the SAVESPTR() */
+                save_gp(PL_firstgv, 0);
+                save_gp(PL_secondgv, 0);
+                /* we don't want modifications localized */
+                GvINTRO_off(PL_firstgv);
+                GvINTRO_off(PL_secondgv);
                SAVESPTR(GvSV(PL_firstgv));
                SAVESPTR(GvSV(PL_secondgv));
            }
 
+            gimme = G_SCALAR;
            PUSHBLOCK(cx, CXt_NULL, PL_stack_base);
            if (!(flags & OPf_SPECIAL)) {
                cx->cx_type = CXt_SUB;
-               cx->blk_gimme = G_SCALAR;
                /* If our comparison routine is already active (CvDEPTH is
                 * is not 0),  then PUSHSUB does not increase the refcount,
                 * so we have to do it ourselves, because the LEAVESUB fur-
@@ -1782,12 +1789,10 @@ S_sortcv(pTHX_ SV *const a, SV *const b)
     PL_op = PL_sortcop;
     CALLRUNOPS(aTHX);
     PL_curcop = cop;
-    if (PL_stack_sp != PL_stack_base + 1) {
-       assert(PL_stack_sp == PL_stack_base);
-       result = SvIV(&PL_sv_undef);
-    }
-    else
-        result = SvIV(*PL_stack_sp);
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
+    result = SvIV(*PL_stack_sp);
 
     while (PL_scopestack_ix > oldscopeix) {
        LEAVE;
@@ -1835,12 +1840,10 @@ S_sortcv_stacked(pTHX_ SV *const a, SV *const b)
     PL_op = PL_sortcop;
     CALLRUNOPS(aTHX);
     PL_curcop = cop;
-    if (PL_stack_sp != PL_stack_base + 1) {
-       assert(PL_stack_sp == PL_stack_base);
-       result = SvIV(&PL_sv_undef);
-    }
-    else
-        result = SvIV(*PL_stack_sp);
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
+    result = SvIV(*PL_stack_sp);
 
     while (PL_scopestack_ix > oldscopeix) {
        LEAVE;
@@ -1869,9 +1872,11 @@ S_sortcv_xsub(pTHX_ SV *const a, SV *const b)
     *++SP = b;
     PUTBACK;
     (void)(*CvXSUB(cv))(aTHX_ cv);
-    if (PL_stack_sp != PL_stack_base + 1)
-       Perl_croak(aTHX_ "Sort subroutine didn't return single value");
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
     result = SvIV(*PL_stack_sp);
+
     while (PL_scopestack_ix > oldscopeix) {
        LEAVE;
     }