allow sort() reentrancy (variant of patch suggested by

Hugo van der Sanden)

p4raw-id: //depot/perl@5975

1 files changed, 10 insertions, 7 deletions

diff --git a/pp_ctl.c b/pp_ctl.c
index 64c706ee36..2308d35814 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -883,15 +883,18 @@ PP(pp_sort)
 
 	    CATCH_SET(TRUE);
 	    PUSHSTACKi(PERLSI_SORT);
-	    if (PL_sortstash != stash) {
-		PL_firstgv = gv_fetchpv("a", TRUE, SVt_PV);
-		PL_secondgv = gv_fetchpv("b", TRUE, SVt_PV);
-		PL_sortstash = stash;
+	    if (!hasargs && !is_xsub) {
+		if (PL_sortstash != stash || !PL_firstgv || !PL_secondgv) {
+		    SAVESPTR(PL_firstgv);
+		    SAVESPTR(PL_secondgv);
+		    PL_firstgv = gv_fetchpv("a", TRUE, SVt_PV);
+		    PL_secondgv = gv_fetchpv("b", TRUE, SVt_PV);
+		    PL_sortstash = stash;
+		}
+		SAVESPTR(GvSV(PL_firstgv));
+		SAVESPTR(GvSV(PL_secondgv));
 	    }
 
-	    SAVESPTR(GvSV(PL_firstgv));
-	    SAVESPTR(GvSV(PL_secondgv));
-
 	    PUSHBLOCK(cx, CXt_NULL, PL_stack_base);
 	    if (!(PL_op->op_flags & OPf_SPECIAL)) {
 		cx->cx_type = CXt_SUB;