Fix a free(NULL) in min_heap.h

Backport of 6f20492fa27f08

1 files changed, 1 insertions, 1 deletions

diff --git a/min_heap.h b/min_heap.h
index 4fc83c01..14d8e370 100644
--- a/min_heap.h
+++ b/min_heap.h
@@ -56,7 +56,7 @@ int min_heap_elem_greater(struct event *a, struct event *b)
 }
 
 void min_heap_ctor(min_heap_t* s) { s->p = 0; s->n = 0; s->a = 0; }
-void min_heap_dtor(min_heap_t* s) { free(s->p); }
+void min_heap_dtor(min_heap_t* s) { if(s->p) free(s->p); }
 void min_heap_elem_init(struct event* e) { e->min_heap_idx = -1; }
 int min_heap_empty(min_heap_t* s) { return 0u == s->n; }
 unsigned min_heap_size(min_heap_t* s) { return s->n; }