From 68758b7e8e88f1454d96a20190af66c2653036ab Mon Sep 17 00:00:00 2001
From: Nathan Daly <nhdaly@gmail.com>
Date: Thu, 15 Oct 2020 23:49:31 -0400
Subject: [PATCH] Extend `static_show()` escaping to any illegal identifier via
 var"".

Previously, it was only escaping names with a `#` in them, but now it
will escape all names that are illegal identifiers.

Before:
```julia
julia> struct var"a%b+c" x::Int end

julia> println(static_shown(var"a%b+c"))
Main.a%b+c

julia> println(static_shown(var"a%b+c"(1)))
Main.a%b+c(x=1)
```
After:
```julia
julia> struct var"a%b+c" x::Int end

julia> println(static_shown(var"a%b+c"))
Main.var"a%b+c"

julia> println(static_shown(var"a%b+c"(1)))
Main.var"a%b+c"(x=1)
```
---
 src/rtutils.c | 5 ++++-
 test/show.jl  | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/rtutils.c b/src/rtutils.c
index 9e19c6f431f69..8ace4f0cb866b 100644
--- a/src/rtutils.c
+++ b/src/rtutils.c
@@ -625,7 +625,10 @@ static size_t jl_static_show_x_sym_escaped(JL_STREAM *out, jl_sym_t *name) JL_NO
     size_t n = 0;
 
     char *sn = jl_symbol_name(name);
-    int hidden = strchr(sn, '#') != 0;
+    int hidden = 0;
+    if (!jl_is_identifier(sn) || jl_is_operator(sn)) {
+        hidden = 1;
+    }
 
     if (hidden) {
         n += jl_printf(out, "var\"");
diff --git a/test/show.jl b/test/show.jl
index 8ce3aee3de18c..3350ef6647251 100644
--- a/test/show.jl
+++ b/test/show.jl
@@ -1339,6 +1339,7 @@ end
 # PR #38049
 struct var"#X#" end
 var"#f#"() = 2
+struct var"%X%" end  # Invalid name without '#'
 
 @test static_shown(var"#X#") == "$(@__MODULE__).var\"#X#\""
 # (Just to make this test more sustainable,) for types, we don't necesssarily need to test
@@ -1350,6 +1351,8 @@ var"#f#"() = 2
     @testset for v in (
             var"#X#",
             var"#X#"(),
+            var"%X%",
+            var"%X%"(),
             Vector,
             Vector{<:Any},
             Vector{var"#X#"},