fix macroexpansion scope miscalculation

previously, we were treating hygienic-scope as also introducing a new scope-block
that was wrong (and inconsistent with previous behavior)

also, we were failing to set the outermost flag when entering a
hygienic-scope block, further compounding the above error

fix #23239

Author: vtjnash

src/macroexpand.scm

@@ -377,7 +377,7 @@
              (let ((parent-scope (cons (list env m) parent-scope))
                    (body (cadr e))
                    (m (caddr e)))
-              (resolve-expansion-vars-with-new-env body env m parent-scope inarg)))
+              (resolve-expansion-vars-with-new-env body env m parent-scope inarg #t)))
 
            ;; todo: trycatch
            (else
@@ -407,10 +407,30 @@
                      (and (eq? (car e) '=) (length= e 3)
                           (eventually-call? (cadr e))))))
 
+;; count hygienic / escape pairs
+;; and fold together a list resulting from applying the function to
+;; and block at the same hygienic scope
+(define (resume-on-escape lam e nblocks)
+  (if (or (not (pair? e)) (quoted? e))
+      '()
+      (cond ((memq (car e) '(lambda module toplevel))
+             '())
+            ((eq? (car e) 'hygienic-scope)
+             (resume-on-escape lam (cadr e) (+ nblocks 1)))
+            ((eq? (car e) 'escape)
+             (if (= nblocks 0)
+                 (lam (cadr e))
+                 (resume-on-escape lam (cadr e) (- nblocks 1))))
+            (else
+             (foldl (lambda (a l) (append! l (resume-on-escape lam a nblocks)))
+                    '()
+                    (cdr e))))))
+
 (define (find-declared-vars-in-expansion e decl (outer #t))
   (cond ((or (not (pair? e)) (quoted? e)) '())
         ((eq? (car e) 'escape)  '())
-        ((eq? (car e) 'hygienic-scope)  '())
+        ((eq? (car e) 'hygienic-scope)
+         (resume-on-escape (lambda (e) (find-declared-vars-in-expansion e decl outer)) (cadr e) 0))
         ((eq? (car e) decl)     (map decl-var* (cdr e)))
         ((and (not outer) (function-def? e)) '())
         (else
@@ -421,7 +441,8 @@
 (define (find-assigned-vars-in-expansion e (outer #t))
   (cond ((or (not (pair? e)) (quoted? e))  '())
         ((eq? (car e) 'escape)  '())
-        ((eq? (car e) 'hygienic-scope)  '())
+        ((eq? (car e) 'hygienic-scope)
+         (resume-on-escape (lambda (e) (find-assigned-vars-in-expansion e outer)) (cadr e) 0))
         ((and (not outer) (function-def? e))
          ;; pick up only function name
          (let ((fname (cond ((eq? (car e) '=) (decl-var* (cadr e)))
@@ -501,11 +522,12 @@
                (error (string "macro \"" (cadr e) "\" not defined")))
            (if (and (pair? form) (eq? (car form) 'error))
                (error (cadr form)))
-           (let ((form (car form)) ;; form is the expression returned from expand-macros
-                 (modu (cdr form))) ;; modu is the macro's def module
-             `(hygienic-scope
-               ,(julia-expand-macros- (cons modu m) (rename-symbolic-labels form) (- max-depth 1))
-               ,modu))))
+           (let* ((modu (cdr form)) ;; modu is the macro's def module
+                  (form (car form)) ;; form is the expression returned from expand-macros
+                  (form (julia-expand-macros- (cons modu m) form (- max-depth 1))))
+             (if (and (pair? form) (eq? (car form) 'escape))
+                 (cadr form) ; immediately fold away (hygienic-scope (escape ...))
+                 `(hygienic-scope ,form ,modu)))))
         ((eq? (car e) 'module) e)
         ((eq? (car e) 'escape)
          (let ((m (if (null? m) m (cdr m))))

test/core.jl

@@ -4999,7 +4999,7 @@ let a_foo = Foo22256(Bar22256{true}(2))
     @test a_foo.bar.inner == 3
 end
 
-# macro hygiene scope (#22307)
+# macro hygiene scope (#22307, #23239)
 macro a22307()
     return esc(:a22307)
 end
@@ -5013,6 +5013,36 @@ end
 a22307 = 2
 @test c22307() == 2
 
+macro identity23239b(x)
+    return esc(x)
+end
+macro identity23239c(x)
+    return quote
+        $(esc(x))
+    end
+end
+macro assign23239d(x, v)
+    return esc(:($x = $v))
+end
+macro assign23239e(x, v)
+    return quote
+        $(esc(:($x = $v)))
+    end
+end
+macro aa23239()
+    return quote
+        a = 1
+        @identity23239b b = 2
+        @identity23239c c = 3
+        @assign23239d d 4
+        @assign23239e e 5
+        (a, b, c, d, e)
+    end
+end
+f23239() = @aa23239()
+@test @inferred(f23239()) === (1, 2, 3, 4, 5)
+
+
 # issue #22026
 module M22026