syntax_error now throws error;

fix handling of error if no top-level handler is available


git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@440 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/exec.c

@@ -1256,11 +1256,11 @@ Int
 JumpToEnv(Term t) {
   yamop *pos = (yamop *)(PredDollarCatch->LastClause);
   CELL *env;
-  choiceptr first_func = NULL;
+  choiceptr first_func = NULL, B0 = B;
 
   do {
     /* find the first choicepoint that may be a catch */
-    while (B->cp_ap != pos) {
+    while (B != NULL && B->cp_ap != pos) {
       /* we are already doing a catch */
       if (B->cp_ap == (yamop *)(PredHandleThrow->LastClause)) {
 	if (DelayedB == NULL || YOUNGER_CP(B,DelayedB))
@@ -1275,6 +1275,11 @@ JumpToEnv(Term t) {
 	first_func = B;
       B = B->cp_b;
     }
+    /* uncaught throw */
+    if (B == NULL) {
+      B = B0;
+      siglongjmp(RestartEnv,1);
+    }
     /* is it a continuation? */
     env = B->cp_env;
     while (env > ENV)