fix core dump in tabling

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1922 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/exec.c

@@ -1462,7 +1462,7 @@ init_stack(int arity, CELL *pt, int top, choiceptr saved_b)
   B = (choiceptr)ASP;
   B--;
 #ifdef TABLING
-  if (top) {
+  if (top && GLOBAL_root_dep_fr) {
     DepFr_cons_cp(GLOBAL_root_dep_fr) = B;
   }
 #endif /* TABLING */

changes-5.1.html

@@ -16,6 +16,7 @@
 
 <h2>Yap-5.1.3:</h2>
 <ul>
+<li> FIXED: tabling broken (obs from Will Benton).</li>
 <li> FIXED: updates to SWI C-interface and corresponding extensions to
 C-interface .</li>
 <li> FIXED: be careful to give delayarena exactly what it needs to expand.</li>