Don't change -1 as a keyword

Author: davmason

src/native/eventpipe/ep-provider.c

@@ -248,8 +248,12 @@ ep_provider_add_event (
 	// Keyword bits 44-47 are reserved for use by EventSources, and every EventSource sets them all.
 	// We filter out those bits here so later comparisons don't have to take them in to account. Without
 	// filtering, EventSources wouldn't show up with Keywords=0.
-	int64_t session_mask = ~0xF00000000000;
-	keywords &= session_mask;
+	uint64_t session_mask = ~0xF00000000000;
+	// -1 is special, it means all keywords. Don't change it.
+	uint64_t all_keywords = (uint64_t)(-1);
+	if (keywords != all_keywords) {
+		keywords &= session_mask;
+	}
 
 	EventPipeEvent *instance = ep_event_alloc (
 		provider,