fix garbage collection of vectors returned by ft_evaluate()

src/frontend/com_let.c

@@ -108,7 +108,7 @@ com_let(wordlist *wl)
             indices[numdims++] = j;
 
             /* va: garbage collection for t, if pnode `names' is no simple value */
-            if (names != NULL && names->pn_value == NULL && t != NULL)
+            if (names && !names->pn_value && t)
                 vec_free(t);
             free_pnode(names); /* frees also t, if pnode `names' is simple value */
 
@@ -235,7 +235,7 @@ com_let(wordlist *wl)
 
 quit:
     /* va: garbage collection for t, if pnode `names' is no simple value */
-    if (names != NULL && names->pn_value == NULL && t != NULL)
+    if (names && !names->pn_value && t)
         vec_free(t);
     free_pnode(names); /* frees also t, if pnode `names' is simple value */
     tfree(p);

src/frontend/cpitf.c

@@ -317,7 +317,7 @@ cp_istrue(wordlist *wl)
     rv = !vec_iszero(v);
 
     /* va: garbage collection for v, if pnode names is no simple value */
-    if (names->pn_value == NULL && v != NULL)
+    if (names && !names->pn_value && v)
         vec_free(v);
     free_pnode(names); /* free also v, if pnode names is simple value */
 

src/frontend/device.c

@@ -1350,11 +1350,10 @@ com_alter_common(wordlist *wl, int do_model)
 
     if_setparam(ft_curckt->ci_ckt, &dev, param, dv, do_model);
 
+done:
     /* va: garbage collection for dv, if pnode names is no simple value */
-    if (names->pn_value == NULL && dv != NULL)
+    if (names && !names->pn_value && dv)
         vec_free(dv);
-
-done:
     free_pnode(names); /* free also dv, if pnode names is simple value */
 }