hostattrs accessors: call PREPROCESS-HOST in some situations

Signed-off-by: Sean Whitton <spwhitton@spwhitton.name>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/host.lisp b/src/host.lisp
index acda791..a449d3c 100644
--- a/src/host.lisp
+++ b/src/host.lisp
@@ -80,6 +80,10 @@ attributes, so that implementations of ESTABLISH-CONNECTION can push new
 attributes (typically to request prerequisite data) without disturbing host
 values higher up the call stack."))
 
+(defparameter *preprocessing-host* nil
+  "HOST value currently being preprocessed.
+Used by GET-HOSTATTRS to break infinite loops.")
+
 (defmethod preprocess-host ((host preprocessed-host))
   (shallow-copy-host host))
 
@@ -87,7 +91,8 @@ values higher up the call stack."))
   (let ((*host* (make-instance
                  'preprocessed-host
                  :hostattrs (copy-list (hostattrs host))
-                 :propspec (preprocess-propspec (host-propspec host)))))
+                 :propspec (preprocess-propspec (host-propspec host))))
+        (*preprocessing-host* host))
     (propappattrs (eval-propspec (host-propspec *host*)))
     *host*))