Fix leak with strings, re issue #162

src/heap.c

@@ -171,17 +171,34 @@ void trim_heap(query *q)
 
 		cell *c = a->heap;
 
-		for (pl_idx_t i = 0; i < a->hp; i++, c++)
+		for (pl_idx_t i = 0; i < a->hp; i++, c++) {
 			unshare_cell(c);
+			init_cell(c);
+		}
 
 		page *save = a;
 		q->pages = a = a->next;
 		free(save->heap);
 		free(save);
 	}
+
+#define DEBUG_TRIM 0
+
+	const page *a = q->pages;
+
+	if (DEBUG_TRIM) printf("*** %u : %u -> %u\n", a->nbr, q->st.hp, a->hp);
+
+	for (pl_idx_t i = q->st.hp; a && (i < a->hp); i++) {
+		cell *c = a->heap + i;
+		if (DEBUG_TRIM) if (is_managed(c)) printf("*** got one\n");
+		unshare_cell(c);
+		init_cell(c);
+	}
+
+	if (DEBUG_TRIM) printf("\n");
 }
 
-static bool is_in_ref_list(const cell *c, pl_idx_t c_ctx, const reflist *rlist)
+bool is_in_ref_list(const cell *c, pl_idx_t c_ctx, const reflist *rlist)
 {
 	while (rlist) {
 		if ((c == rlist->ptr) && (c_ctx == rlist->ctx))
@@ -497,8 +514,8 @@ static cell *deep_clone2_to_tmp(query *q, cell *p1, pl_idx_t p1_ctx, unsigned de
 
 	cell *save_p1 = p1;
 	pl_idx_t save_p1_ctx = p1_ctx;
-	//p1 = deref(q, p1, p1_ctx);
-	//p1_ctx = q->latest_ctx;
+	p1 = deref(q, p1, p1_ctx);
+	p1_ctx = q->latest_ctx;
 
 	pl_idx_t save_idx = tmp_heap_used(q);
 	cell *tmp = alloc_on_tmp(q, 1);
@@ -664,29 +681,23 @@ cell *clone_to_heap(query *q, bool prefix, cell *p1, unsigned extras)
 
 	if (prefix) {
 		// Needed for follow() to work
-		tmp->tag = TAG_INTERNED;
-		tmp->arity = 0;
+		*tmp = (cell){0};
+		tmp->tag = TAG_EMPTY;
 		tmp->nbr_cells = 1;
 		tmp->flags = FLAG_BUILTIN;
-
-		static builtins *s_fn_ptr = NULL;
-
-		if (!s_fn_ptr)
-			s_fn_ptr = get_fn_ptr(fn_iso_true_0);
-
-		tmp->fn_ptr = s_fn_ptr;
 	}
 
 	cell *src = p1, *dst = tmp+(prefix?1:0);
 
-	for (pl_idx_t i = 0; i < p1->nbr_cells; i++, dst++) {
-		*dst = *src++;
-		share_cell(dst);
+	for (pl_idx_t i = 0; i < p1->nbr_cells; i++, dst++, src++) {
+		*dst = *src;
+		share_cell(src);
 
-		if (is_var(dst) && !is_ref(dst)) {
-			dst->flags |= FLAG_VAR_REF;
-			dst->var_ctx = q->st.curr_frame;
-		}
+		if (!is_var(src) || is_ref(src))
+			continue;
+
+		dst->flags |= FLAG_VAR_REF;
+		dst->var_ctx = q->st.curr_frame;
 	}
 
 	return tmp;