From 36169a922c64916884608b7cb3032a174efeab75 Mon Sep 17 00:00:00 2001
From: Simeon Schaub <simeondavidschaub99@gmail.com>
Date: Wed, 17 Feb 2021 21:33:33 +0100
Subject: [PATCH] fix #39705: lowering of Expr(:||) (#39709)

(cherry picked from commit 0858864409596d158d2ab7f5bc49308c1f718bdc)
---
 src/julia-syntax.scm | 5 ++++-
 test/cartesian.jl    | 4 ++++
 test/syntax.jl       | 4 ++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/julia-syntax.scm b/src/julia-syntax.scm
index 4debe7324598e..48b175680c535 100644
--- a/src/julia-syntax.scm
+++ b/src/julia-syntax.scm
@@ -1927,7 +1927,10 @@
          (stmts (if blk? (cdr (butlast test)) '()))
          (test  (if blk? (last test) test)))
     (if (and (pair? test) (memq (car test) '(&& |\|\||)))
-        (let ((clauses `(,(car test) ,@(map expand-forms (cdr (flatten-ex (car test) test))))))
+        (let* ((clauses `(,(car test) ,@(map expand-forms (cdr (flatten-ex (car test) test)))))
+               (clauses (if (null? (cdr clauses))
+                            (if (eq? (car clauses) '&&) '(true) '(false))
+                            clauses)))
           `(if ,(if blk?
                     `(block ,@(map expand-forms stmts) ,clauses)
                     clauses)
diff --git a/test/cartesian.jl b/test/cartesian.jl
index 32c3e1fb0a4e6..af0bc466e3d04 100644
--- a/test/cartesian.jl
+++ b/test/cartesian.jl
@@ -405,3 +405,7 @@ end
 
     @test @inferred(intersect(I, J)) == CartesianIndices((2:3, 4:5))
 end
+
+# issue #39705
+f39705() = Base.Cartesian.@nany 0 _ -> true
+@test f39705() === false
diff --git a/test/syntax.jl b/test/syntax.jl
index 68f32b600b79d..b032283523c4f 100644
--- a/test/syntax.jl
+++ b/test/syntax.jl
@@ -2700,3 +2700,7 @@ end
 
 @test eval(Expr(:string, "a", Expr(:string, "b", "c"))) == "abc"
 @test eval(Expr(:string, "a", Expr(:string, "b", Expr(:string, "c")))) == "abc"
+
+# issue #39705
+@eval f39705(x) = $(Expr(:||)) && x
+@test f39705(1) === false