gc: sys:gc function must not reset full_gc flag.

* gc.c (gc_wrap): We must not set full_gc according to the
argument, but only set it to 1 if the argument requests
full GC. full_gc is set to 1 for some reason having to do with
correctness; only the garbage collector can reset full_gc
back to 0, otherwise incorrect behavior will ensue.

1 files changed, 2 insertions, 1 deletions

diff --git a/gc.c b/gc.c
index f3ce3275..c2a4f657 100644
--- a/gc.c
+++ b/gc.c
@@ -974,7 +974,8 @@ static val gc_wrap(val full)
 {
   if (gc_enabled) {
 #if CONFIG_GEN_GC
-    full_gc = !null_or_missing_p(full);
+    if (!null_or_missing_p(full))
+      full_gc = 1;
 #endif
     gc();
     return t;