X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/6ee1970906d33f0b1b2be20e2f8a4521a6ca514f..7b7947024fedb0bb7a0ea3ccb0029f6060de901b:/src/pset-proto.lisp?ds=sidebyside

diff --git a/src/pset-proto.lisp b/src/pset-proto.lisp
index e16e04c..61793b5 100644
--- a/src/pset-proto.lisp
+++ b/src/pset-proto.lisp
@@ -317,7 +317,8 @@ (defmacro default-slot-from-property
    We initialize SLOT in INSTANCE.  In full: if PSET contains a property
    called NAME, then convert it to TYPE, bind the value to PVAR and evaluate
    CONVERT-FORMS -- these default to just using the property value.  If
-   there's no property, and the slot is named in SLOT-NAMES and currently
+   there's no property, and DEFAULT-FORMS contains at least one non-
+   declaration form, and the slot is named in SLOT-NAMES and currently
    unbound, then evaluate DEFAULT-FORMS and use their value to compute the
    slot value."
 
@@ -333,7 +334,8 @@ (defmacro default-slot-from-property
 	       (setf (slot-value ,instance ,slot)
 		     (with-default-error-location (,floc)
 		       ,@(or convert-forms `(,pvar))))
-	       (default-slot (,instance ,slot ,slot-names)
-		 ,@body)))))))
+	       ,@(and body
+		      `((default-slot (,instance ,slot ,slot-names)
+			  ,@body)))))))))
 
 ;;;----- That's all, folks --------------------------------------------------