From 93b29d64606a2374bf2b3ccb23bda5bedf05b2d3 Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Wed, 27 Jun 2018 13:50:08 -0400
Subject: [PATCH] fix #27352, disallow `print`/`string` of `nothing`

---
 base/show.jl |  1 +
 test/show.jl | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/base/show.jl b/base/show.jl
index ee90da6c2acc1..5785792e190ea 100644
--- a/base/show.jl
+++ b/base/show.jl
@@ -557,6 +557,7 @@ function show(io::IO, tn::Core.TypeName)
 end
 
 show(io::IO, ::Nothing) = print(io, "nothing")
+print(io::IO, ::Nothing) = throw(MethodError(print, (io, nothing)))
 show(io::IO, b::Bool) = print(io, b ? "true" : "false")
 show(io::IO, n::Signed) = (write(io, string(n)); nothing)
 show(io::IO, n::Unsigned) = print(io, "0x", string(n, pad = sizeof(n)<<1, base = 16))
diff --git a/test/show.jl b/test/show.jl
index 2367ec56a4e93..22a5d27066b34 100644
--- a/test/show.jl
+++ b/test/show.jl
@@ -1248,3 +1248,13 @@ h_line() = f_line()
     │╻╷ f_line
     ││╻  g_line
     ││╻  g_line""")
+
+# issue #27352
+@test_throws MethodError print(nothing)
+@test_throws MethodError print(stdout, nothing)
+@test_throws MethodError string(nothing)
+@test_throws MethodError string(1, "", nothing)
+@test_throws MethodError let x = nothing; "x = $x" end
+@test let x = nothing; "x = $(repr(x))" end == "x = nothing"
+@test_throws MethodError `/bin/foo $nothing`
+@test_throws MethodError `$nothing`