From fe593469a057bce9f3a905141dbfca360edbdac5 Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Thu, 14 May 2020 19:34:39 -0700
Subject: [PATCH] Left fold ImmutableDict(args::Pair...) (#35871)

Currently, the behavior of `Dict(pairs...)` and
`Base.ImmutableDict(pairs...)` are different:

    julia> Dict(:a => 1, :a => 2)[:a]
    2

    julia> Base.ImmutableDict(:a => 1, :a => 2)[:a]
    1

This PR fixes the latter to return 2.
---
 base/dict.jl | 2 +-
 test/dict.jl | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/base/dict.jl b/base/dict.jl
index b3387d84c9ca2..109538e70cf4f 100644
--- a/base/dict.jl
+++ b/base/dict.jl
@@ -742,7 +742,7 @@ Create a new entry in the `ImmutableDict` for a `key => value` pair
 ImmutableDict
 ImmutableDict(KV::Pair{K,V}) where {K,V} = ImmutableDict{K,V}(KV[1], KV[2])
 ImmutableDict(t::ImmutableDict{K,V}, KV::Pair) where {K,V} = ImmutableDict{K,V}(t, KV[1], KV[2])
-ImmutableDict(KV::Pair, rest::Pair...) = ImmutableDict(ImmutableDict(rest...), KV)
+ImmutableDict(KV::Pair, rest::Pair...) = ImmutableDict(ImmutableDict(KV), rest...)
 
 function in(key_value::Pair, dict::ImmutableDict, valcmp=(==))
     key, value = key_value
diff --git a/test/dict.jl b/test/dict.jl
index 16a1b13f62e3b..73e8e5bad6e2e 100644
--- a/test/dict.jl
+++ b/test/dict.jl
@@ -722,7 +722,8 @@ import Base.ImmutableDict
     v = [k1 => v1, k2 => v2]
     d5 = ImmutableDict(v...)
     @test d5 == d2
-    @test collect(d5) == v
+    @test reverse(collect(d5)) == v
+    @test ImmutableDict(:a => 1, :a => 2)[:a] == 2
 
     @test !haskey(ImmutableDict(-0.0=>1), 0.0)
 end