From 11dcd63b0fe874eefdcb07a66f05880d78b429ba Mon Sep 17 00:00:00 2001
From: Iblis Lin <iblis@hs.ntnu.edu.tw>
Date: Mon, 15 Jan 2018 10:40:58 +0800
Subject: [PATCH] markdown: Base.copy for Markdown.MD (#25315)

---
 base/markdown/parse/parse.jl |  1 +
 test/markdown.jl             | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/base/markdown/parse/parse.jl b/base/markdown/parse/parse.jl
index b9a2f9c1f36c2..a47dcc627f481 100644
--- a/base/markdown/parse/parse.jl
+++ b/base/markdown/parse/parse.jl
@@ -26,6 +26,7 @@ Base.setindex!(md::MD, args...) = setindex!(md.content, args...)
 Base.endof(md::MD) = endof(md.content)
 Base.length(md::MD) = length(md.content)
 Base.isempty(md::MD) = isempty(md.content)
+Base.copy(md::MD) = MD(copy(md.content), copy(md.meta))
 
 ==(a::MD, b::MD) = (html(a) == html(b))
 
diff --git a/test/markdown.jl b/test/markdown.jl
index dcdce625a7510..4b9df5512e926 100644
--- a/test/markdown.jl
+++ b/test/markdown.jl
@@ -1079,3 +1079,17 @@ t = """
     :-- | --:
     1   |   2"""
 @test sprint(Markdown.term, Markdown.parse(t), 0) == "a b\n– –\n1 2\n"
+
+# test Base.copy
+let
+    md = doc"test"
+    md′ = copy(md)
+    @test length(md) == length(md′) == 1
+    push!(md, "new")
+    @test length(md) == 2
+    @test length(md′) == 1
+
+    @test !haskey(md.meta, :foo)
+    md.meta[:foo] = 42
+    @test !haskey(md′.meta, :foo)
+end