fix JuliaLang#41416, splatted default argument lost with keyword argument (JuliaLang#41427)

Author: JeffBezanson

src/ast.scm

@@ -319,7 +319,7 @@
          (bad-formal-argument v))
         (else
          (case (car v)
-           ((... kw)
+           ((...)
 	    (arg-name (cadr v)) ;; to check for errors
 	    (decl-var (cadr v)))
            ((|::|)
@@ -330,6 +330,8 @@
             (if (nospecialize-meta? v #t)
                 (arg-name (caddr v))
                 (bad-formal-argument v)))
+           ((kw)
+            (arg-name (cadr v)))
            (else (bad-formal-argument v))))))
 
 (define (arg-type v)
@@ -349,6 +351,8 @@
             (if (nospecialize-meta? v #t)
                 (arg-type (caddr v))
                 (bad-formal-argument v)))
+           ((kw)
+            (arg-type (cadr v)))
            (else (bad-formal-argument v))))))
 
 ;; convert a lambda list into a list of just symbols

src/julia-syntax.scm

@@ -442,9 +442,12 @@
          ;; 1-element list of vararg argument, or empty if none
          (vararg (let* ((l (if (null? pargl) '() (last pargl)))
                         ;; handle vararg with default value
-                        (l (if (kwarg? l) (cadr l) l)))
-                   (if (or (vararg? l) (varargexpr? l))
+                        (l- (if (kwarg? l) (cadr l) l)))
+                   (if (or (vararg? l-) (varargexpr? l-))
                        (list l) '())))
+         ;; expression to forward varargs to another call
+         (splatted-vararg (if (null? vararg) '()
+                              (list `(... ,(arg-name (car vararg))))))
          ;; positional args with vararg
          (pargl-all pargl)
          ;; positional args without vararg
@@ -520,8 +523,7 @@
                                        ,@(if ordered-defaults keynames vals)
                                        ,@(if (null? restkw) '() `((call (top pairs) (call (core NamedTuple)))))
                                        ,@(map arg-name pargl)
-                                       ,@(if (null? vararg) '()
-                                             (list `(... ,(arg-name (car vararg)))))))))
+                                       ,@splatted-vararg))))
                (if ordered-defaults
                    (scopenest keynames vals ret)
                    ret))))
@@ -579,16 +581,13 @@
                 ,@(if (null? restkw)
                       `((if (call (top isempty) ,rkw)
                             (null)
-                            (call (top kwerr) ,kw ,@(map arg-name pargl)
-                                  ,@(if (null? vararg) '()
-                                        (list `(... ,(arg-name (car vararg))))))))
+                            (call (top kwerr) ,kw ,@(map arg-name pargl) ,@splatted-vararg)))
                       '())
                 (return (call ,mangled  ;; finally, call the core function
                               ,@keynames
                               ,@(if (null? restkw) '() (list rkw))
                               ,@(map arg-name pargl)
-                              ,@(if (null? vararg) '()
-                                    (list `(... ,(arg-name (car vararg)))))))))))
+                              ,@splatted-vararg))))))
         ;; return primary function
         ,(if (not (symbol? name))
              '(null) name)))))

test/keywordargs.jl

@@ -380,3 +380,10 @@ f40964(xs::Int...=1; k = 2) = (xs, k)
 @test f40964() === ((1,), 2)
 @test f40964(7, 8) === ((7,8), 2)
 @test f40964(7, 8, k=0) === ((7,8), 0)
+# issue #41416
+@test f40964(; k = 1) === ((1,), 1)
+f41416(a...="a"; b=true) = (b, a)
+@test f41416()           === (true, ("a",))
+@test f41416(;b=false)   === (false, ("a",))
+@test f41416(33)         === (true, (33,))
+@test f41416(3; b=false) === (false, (3,))