fix #25652, let scope error with destructuring (#25837)

Author: JeffBezanson

Diff for: src/julia-syntax.scm

@@ -1191,11 +1191,21 @@
                      (eq? (caadar binds) 'tuple))
                 (let ((vars (lhs-vars (cadar binds))))
                   (loop (cdr binds)
-                        `(scope-block
-                          (block
-                           ,@(map (lambda (v) `(local-def ,v)) vars)
-                           ,(car binds)
-                           ,blk)))))
+                        (if (expr-contains-p (lambda (x) (memq x vars)) (caddr (car binds)))
+                            ;; use more careful lowering if there are name conflicts. issue #25652
+                            (let ((temp (make-ssavalue)))
+                              `(block
+                                (= ,temp ,(caddr (car binds)))
+                                (scope-block
+                                 (block
+                                  ,@(map (lambda (v) `(local-def ,v)) vars)
+                                  (= ,(cadr (car binds)) ,temp)
+                                  ,blk))))
+                            `(scope-block
+                              (block
+                               ,@(map (lambda (v) `(local-def ,v)) vars)
+                               ,(car binds)
+                               ,blk))))))
                (else (error "invalid let syntax"))))
              (else (error "invalid let syntax")))))))))
 

Diff for: test/core.jl

@@ -3939,6 +3939,15 @@ let ex = quote
     @test ex.args[2] == :test
 end
 
+# issue #25652
+x25652 = 1
+x25652_2 = let (x25652, _) = (x25652, nothing)
+    x25652 = x25652 + 1
+    x25652
+end
+@test x25652_2 == 2
+@test x25652 == 1
+
 # issue #15180
 function f15180(x::T) where T
     X = Vector{T}(uninitialized, 1)