[nci]: Fix NCI::Utils::ncifunc -- don't free up arguments to NCI unti…

…l we've established the return value.

runtime/parrot/library/NCI/Utils.pir

@@ -431,25 +431,30 @@ C<signature> are:
     func = find_lex 'func'
     (retv :slurpy) = func(args :flat)
 
+    .local int rett
+    $S0 = substr signature, 0, 1
+    rett = iseq $S0, 't'
+    unless rett goto have_retv
+    .local string rets
+    retv = pop retv
+    rets = null
+    if null retv goto have_retv
+    .local string rets
+    rets = 'str_new'(interp, retv, 0)
+  have_retv:
+
   free_loop:
     unless strfreelist goto free_done
     $P0 = pop strfreelist
     'str_free_cstring'($P0)
     goto free_loop
   free_done:
 
-    $S0 = substr signature, 0, 1
-    if $S0 == 't' goto nci_ret_t
+    if rett goto nci_ret_t
     .return (retv :flat)
 
   nci_ret_t:
-    retv = pop retv                 # get the first value out of the slurpy
-    if null retv goto nci_ret_t_null
-    $S0 = 'str_new'(interp, retv, 0)
-    .return ($S0)
-  nci_ret_t_null:
-    $S0 = null
-    .return ($S0)
+    .return (rets)
 .end
 
 

t/library/nciutils.t

@@ -38,7 +38,7 @@ Testing Perl 6 objects.
 
   have_enough_nci:
     ##  set our plan
-    plan(13)
+    plan(14)
 
     ##  make sure we can load the NCI::Utils library
     push_eh load_fail
@@ -71,6 +71,11 @@ Testing Perl 6 objects.
     ( $I0 ) = $P0('hello', 'hello')
     is($I0, 0, 'strcmp == 0')
 
+    $P0 = ncifunc(null_pmc, 'strstr', 'ttt')
+    ( $S0 ) = $P0('hello', 'e')
+    is($S0, 'ello', 'strstr("hello", "e")')
+
+
     ##  load a library
     .local pmc libnci_test
     libnci_test = loadlib "libnci_test"