obj_print: uw guard frame only when circ printing.

* lib.c (obj_print): Only set up and tear down the
continuation-blocking unwind frame when doing circle
printing.

1 files changed, 4 insertions, 2 deletions

diff --git a/lib.c b/lib.c
index f7b75809..5f92b6c1 100644
--- a/lib.c
+++ b/lib.c
@@ -9497,7 +9497,8 @@ val obj_print(val obj, val out, val pretty)
   struct strm_ctx *volatile ctx = ctx_orig, ctx_struct;
   uw_frame_t cont_guard;
 
-  uw_push_guard(&cont_guard, 1);
+  if (ctx_orig)
+    uw_push_guard(&cont_guard, 1);
 
   uw_simple_catch_begin;
 
@@ -9528,7 +9529,8 @@ val obj_print(val obj, val out, val pretty)
 
   uw_catch_end;
 
-  uw_pop_frame(&cont_guard);
+  if (ctx_orig)
+    uw_pop_frame(&cont_guard);
 
   return ret;
 }