fix #38386, macro defining empty function with escaped name (#38402)

Author: JeffBezanson

src/macroexpand.scm

@@ -383,7 +383,7 @@
                  ,(resolve-expansion-vars-with-new-env (caddr e) env m parent-scope inarg)))
 
            ((= function)
-            (if (and (pair? (cadr e)) (function-def? e))
+            (if (and (pair? (cadr e)) (function-def? e) (length> e 2))
                 ;; in (kw x 1) inside an arglist, the x isn't actually a kwarg
                 `(,(car e) ,(resolve-in-function-lhs (cadr e) env m parent-scope inarg)
                   ,(resolve-expansion-vars-with-new-env (caddr e) env m parent-scope inarg))

test/syntax.jl

@@ -2617,6 +2617,14 @@ end
 
 @test eval(Expr(:if, Expr(:block, Expr(:&&, true, Expr(:call, :(===), 1, 1))), 1, 2)) == 1
 
+# issue #38386
+macro m38386()
+    fname = :f38386
+    :(function $(esc(fname)) end)
+end
+@m38386
+@test isempty(methods(f38386))
+
 @testset "all-underscore varargs on the rhs" begin
     @test ncalls_in_lowered(quote _..., = a end, GlobalRef(Base, :rest)) == 0
     @test ncalls_in_lowered(quote ___..., = a end, GlobalRef(Base, :rest)) == 0