Fix all warnings in the main codebase flagged by -Wsigned-compare

Remember, the code
   int is_less_than(int a, unsigned b) {
      return a < b;
   }
is buggy, since the C integer promotion rules basically turn it into
   int is_less_than(int a, unsigned b) {
      return ((unsigned)a) < b;
   }
and we really want something closer to
   int is_less_than(int a, unsigned b) {
      return a < 0 || ((unsigned)a) < b;
   }
.

Suggested by an example from Ralph Castain

1 files changed, 1 insertions, 1 deletions

diff --git a/minheap-internal.h b/minheap-internal.h
index 0557c2ba..9734a7c7 100644
--- a/minheap-internal.h
+++ b/minheap-internal.h
@@ -95,7 +95,7 @@ int min_heap_elt_is_top(const struct event *e)
 
 int min_heap_erase(min_heap_t* s, struct event* e)
 {
-	if (((unsigned int)-1) != e->ev_timeout_pos.min_heap_idx)
+	if (-1 != e->ev_timeout_pos.min_heap_idx)
 	{
 		struct event *last = s->p[--s->n];
 		unsigned parent = (e->ev_timeout_pos.min_heap_idx - 1) / 2;