pprint: Make sure that lists like (loop . 10) can be printed.

pprint signaled an error when called on improper lists with
a car being a symbol from CL (loop, macrolet, flet, and some others).

diff --git a/NEWS b/NEWS
index a4137d0..141efbd 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,8 @@ changes relative to sbcl-1.0.56:
     use of NCONC in MAKE-LEXENV. (lp#924276)
   * bug fix: ENSURE-DIRECTORIES-EXIST now works when *default-pathname-defaults*
     contains NAME or TYPE components.
+  * bug fix: PPRINT couldn't print improper lists with CARs being some symbols
+    from CL package, e.g. (loop . 10).
   * documentation:
     ** improved docstrings: REPLACE (lp#965592)
 

diff --git a/src/code/pprint.lisp b/src/code/pprint.lisp
index f499bfb..f542878 100644 (file)
--- a/src/code/pprint.lisp
+++ b/src/code/pprint.lisp
@@ -1142,7 +1142,8 @@ line break."
            (consp (cdr list))
            (cddr list)
            ;; Filter out (FLET FOO :IN BAR) names.
-           (not (eq :in (third list))))
+           (and (consp (cddr list))
+                (not (eq :in (third list)))))
       (funcall (formatter
                 "~:<~^~W~^ ~@_~:<~@{~:<~^~W~^~3I ~:_~/SB!PRETTY:PPRINT-LAMBDA-LIST/~1I~:@_~@{~W~^ ~_~}~:>~^ ~_~}~:>~1I~@:_~@{~W~^ ~_~}~:>")
                stream
@@ -1266,7 +1267,9 @@ line break."
 
 (defun pprint-defmethod (stream list &rest noise)
   (declare (ignore noise))
-  (if (consp (third list))
+  (if (and (consp (cdr list))
+           (consp (cddr list))
+           (consp (third list)))
       (pprint-defun stream list)
       (funcall (formatter
                 "~:<~^~W~^ ~@_~:I~W~^ ~W~^ ~:_~/SB!PRETTY:PPRINT-LAMBDA-LIST/~1I~@{ ~_~W~}~:>")
@@ -1373,7 +1376,7 @@ line break."
   (declare (ignore noise))
   (destructuring-bind (loop-symbol . clauses) list
     (declare (ignore loop-symbol))
-    (if (or (null clauses) (consp (car clauses)))
+    (if (or (atom clauses) (consp (car clauses)))
         (pprint-spread-fun-call stream list)
         (pprint-extended-loop stream list))))
 

diff --git a/tests/pprint.impure.lisp b/tests/pprint.impure.lisp
index 038af4d..4e6d8a3 100644 (file)
--- a/tests/pprint.impure.lisp
+++ b/tests/pprint.impure.lisp
@@ -278,5 +278,18 @@
     (assert (eq orig (pprint-dispatch 'some-symbol)))
     (assert (not (eq alt orig)))))
 
+(with-test (:name :pprint-improper-list)
+  (let* ((max-length 10)
+         (stream (make-broadcast-stream))
+         (errors
+           (loop for symbol being the symbol in :cl
+                 nconc
+                 (loop for i from 1 below max-length
+                       for list = (cons symbol 10) then (cons symbol list)
+                       when (nth-value 1 (ignore-errors (pprint list stream)))
+                       collect (format nil "(~{~a ~}~a . 10)" (butlast list) symbol)))))
+    (when errors
+      (error "Can't PPRINT imporper lists: ~a" errors))))
+
 \f
 ;;; success