From 98de9de2816295fec775d3bc0ef9f279d6356a17 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 27 Aug 2015 15:59:00 -0700
Subject: [PATCH 1/3] No deduplication in union of tuple element types

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d9a36c34cdf..43856b535e2 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -3119,7 +3119,7 @@ namespace ts {
         }
 
         function resolveTupleTypeMembers(type: TupleType) {
-            let arrayType = resolveStructuredTypeMembers(createArrayType(getUnionType(type.elementTypes)));
+            let arrayType = resolveStructuredTypeMembers(createArrayType(getUnionType(type.elementTypes, /*noDeduplication*/ true)));
             let members = createTupleTypeMemberSymbols(type.elementTypes);
             addInheritedMembers(members, arrayType.properties);
             setObjectTypeMembers(type, members, arrayType.callSignatures, arrayType.constructSignatures, arrayType.stringIndexType, arrayType.numberIndexType);

From 1b08f8adc9ae1fcccd6f6e6e7fadff715ed2e038 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 27 Aug 2015 16:12:04 -0700
Subject: [PATCH 2/3] Adding tests

---
 tests/cases/compiler/recursiveTupleTypes1.ts | 12 ++++++++++++
 tests/cases/compiler/recursiveTupleTypes2.ts | 12 ++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 tests/cases/compiler/recursiveTupleTypes1.ts
 create mode 100644 tests/cases/compiler/recursiveTupleTypes2.ts

diff --git a/tests/cases/compiler/recursiveTupleTypes1.ts b/tests/cases/compiler/recursiveTupleTypes1.ts
new file mode 100644
index 00000000000..82559eccfad
--- /dev/null
+++ b/tests/cases/compiler/recursiveTupleTypes1.ts
@@ -0,0 +1,12 @@
+interface Tree1 {
+    children: [Tree1, Tree2];
+}
+
+interface Tree2 {
+    children: [Tree2, Tree1];
+}
+
+let tree1: Tree1;
+let tree2: Tree2;
+tree1 = tree2;
+tree2 = tree1;
diff --git a/tests/cases/compiler/recursiveTupleTypes2.ts b/tests/cases/compiler/recursiveTupleTypes2.ts
new file mode 100644
index 00000000000..78c8efa82a4
--- /dev/null
+++ b/tests/cases/compiler/recursiveTupleTypes2.ts
@@ -0,0 +1,12 @@
+interface Tree1 {
+    children: [Tree1, Tree2];
+}
+
+interface Tree2 {
+    children: [Tree2, Tree2];
+}
+
+let tree1: Tree1;
+let tree2: Tree2;
+tree1 = tree2;
+tree2 = tree1;

From e6dc58efb9e00824c29c50c46bc6f80a01b1b1f6 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 27 Aug 2015 16:12:31 -0700
Subject: [PATCH 3/3] Accepting new baselines

---
 .../reference/recursiveTupleTypes1.js         | 20 ++++++++++
 .../reference/recursiveTupleTypes1.symbols    | 35 ++++++++++++++++++
 .../reference/recursiveTupleTypes1.types      | 37 +++++++++++++++++++
 .../reference/recursiveTupleTypes2.js         | 20 ++++++++++
 .../reference/recursiveTupleTypes2.symbols    | 35 ++++++++++++++++++
 .../reference/recursiveTupleTypes2.types      | 37 +++++++++++++++++++
 6 files changed, 184 insertions(+)
 create mode 100644 tests/baselines/reference/recursiveTupleTypes1.js
 create mode 100644 tests/baselines/reference/recursiveTupleTypes1.symbols
 create mode 100644 tests/baselines/reference/recursiveTupleTypes1.types
 create mode 100644 tests/baselines/reference/recursiveTupleTypes2.js
 create mode 100644 tests/baselines/reference/recursiveTupleTypes2.symbols
 create mode 100644 tests/baselines/reference/recursiveTupleTypes2.types

diff --git a/tests/baselines/reference/recursiveTupleTypes1.js b/tests/baselines/reference/recursiveTupleTypes1.js
new file mode 100644
index 00000000000..f4fa8ef4816
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes1.js
@@ -0,0 +1,20 @@
+//// [recursiveTupleTypes1.ts]
+interface Tree1 {
+    children: [Tree1, Tree2];
+}
+
+interface Tree2 {
+    children: [Tree2, Tree1];
+}
+
+let tree1: Tree1;
+let tree2: Tree2;
+tree1 = tree2;
+tree2 = tree1;
+
+
+//// [recursiveTupleTypes1.js]
+var tree1;
+var tree2;
+tree1 = tree2;
+tree2 = tree1;
diff --git a/tests/baselines/reference/recursiveTupleTypes1.symbols b/tests/baselines/reference/recursiveTupleTypes1.symbols
new file mode 100644
index 00000000000..8bd0797f3f6
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes1.symbols
@@ -0,0 +1,35 @@
+=== tests/cases/compiler/recursiveTupleTypes1.ts ===
+interface Tree1 {
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes1.ts, 0, 0))
+
+    children: [Tree1, Tree2];
+>children : Symbol(children, Decl(recursiveTupleTypes1.ts, 0, 17))
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes1.ts, 0, 0))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes1.ts, 2, 1))
+}
+
+interface Tree2 {
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes1.ts, 2, 1))
+
+    children: [Tree2, Tree1];
+>children : Symbol(children, Decl(recursiveTupleTypes1.ts, 4, 17))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes1.ts, 2, 1))
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes1.ts, 0, 0))
+}
+
+let tree1: Tree1;
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes1.ts, 8, 3))
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes1.ts, 0, 0))
+
+let tree2: Tree2;
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes1.ts, 9, 3))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes1.ts, 2, 1))
+
+tree1 = tree2;
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes1.ts, 8, 3))
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes1.ts, 9, 3))
+
+tree2 = tree1;
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes1.ts, 9, 3))
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes1.ts, 8, 3))
+
diff --git a/tests/baselines/reference/recursiveTupleTypes1.types b/tests/baselines/reference/recursiveTupleTypes1.types
new file mode 100644
index 00000000000..9dfdc768ddb
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes1.types
@@ -0,0 +1,37 @@
+=== tests/cases/compiler/recursiveTupleTypes1.ts ===
+interface Tree1 {
+>Tree1 : Tree1
+
+    children: [Tree1, Tree2];
+>children : [Tree1, Tree2]
+>Tree1 : Tree1
+>Tree2 : Tree2
+}
+
+interface Tree2 {
+>Tree2 : Tree2
+
+    children: [Tree2, Tree1];
+>children : [Tree2, Tree1]
+>Tree2 : Tree2
+>Tree1 : Tree1
+}
+
+let tree1: Tree1;
+>tree1 : Tree1
+>Tree1 : Tree1
+
+let tree2: Tree2;
+>tree2 : Tree2
+>Tree2 : Tree2
+
+tree1 = tree2;
+>tree1 = tree2 : Tree2
+>tree1 : Tree1
+>tree2 : Tree2
+
+tree2 = tree1;
+>tree2 = tree1 : Tree1
+>tree2 : Tree2
+>tree1 : Tree1
+
diff --git a/tests/baselines/reference/recursiveTupleTypes2.js b/tests/baselines/reference/recursiveTupleTypes2.js
new file mode 100644
index 00000000000..60dde8ef4d5
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes2.js
@@ -0,0 +1,20 @@
+//// [recursiveTupleTypes2.ts]
+interface Tree1 {
+    children: [Tree1, Tree2];
+}
+
+interface Tree2 {
+    children: [Tree2, Tree2];
+}
+
+let tree1: Tree1;
+let tree2: Tree2;
+tree1 = tree2;
+tree2 = tree1;
+
+
+//// [recursiveTupleTypes2.js]
+var tree1;
+var tree2;
+tree1 = tree2;
+tree2 = tree1;
diff --git a/tests/baselines/reference/recursiveTupleTypes2.symbols b/tests/baselines/reference/recursiveTupleTypes2.symbols
new file mode 100644
index 00000000000..2895f1b5669
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes2.symbols
@@ -0,0 +1,35 @@
+=== tests/cases/compiler/recursiveTupleTypes2.ts ===
+interface Tree1 {
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes2.ts, 0, 0))
+
+    children: [Tree1, Tree2];
+>children : Symbol(children, Decl(recursiveTupleTypes2.ts, 0, 17))
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes2.ts, 0, 0))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes2.ts, 2, 1))
+}
+
+interface Tree2 {
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes2.ts, 2, 1))
+
+    children: [Tree2, Tree2];
+>children : Symbol(children, Decl(recursiveTupleTypes2.ts, 4, 17))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes2.ts, 2, 1))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes2.ts, 2, 1))
+}
+
+let tree1: Tree1;
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes2.ts, 8, 3))
+>Tree1 : Symbol(Tree1, Decl(recursiveTupleTypes2.ts, 0, 0))
+
+let tree2: Tree2;
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes2.ts, 9, 3))
+>Tree2 : Symbol(Tree2, Decl(recursiveTupleTypes2.ts, 2, 1))
+
+tree1 = tree2;
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes2.ts, 8, 3))
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes2.ts, 9, 3))
+
+tree2 = tree1;
+>tree2 : Symbol(tree2, Decl(recursiveTupleTypes2.ts, 9, 3))
+>tree1 : Symbol(tree1, Decl(recursiveTupleTypes2.ts, 8, 3))
+
diff --git a/tests/baselines/reference/recursiveTupleTypes2.types b/tests/baselines/reference/recursiveTupleTypes2.types
new file mode 100644
index 00000000000..9ce8e5daf79
--- /dev/null
+++ b/tests/baselines/reference/recursiveTupleTypes2.types
@@ -0,0 +1,37 @@
+=== tests/cases/compiler/recursiveTupleTypes2.ts ===
+interface Tree1 {
+>Tree1 : Tree1
+
+    children: [Tree1, Tree2];
+>children : [Tree1, Tree2]
+>Tree1 : Tree1
+>Tree2 : Tree2
+}
+
+interface Tree2 {
+>Tree2 : Tree2
+
+    children: [Tree2, Tree2];
+>children : [Tree2, Tree2]
+>Tree2 : Tree2
+>Tree2 : Tree2
+}
+
+let tree1: Tree1;
+>tree1 : Tree1
+>Tree1 : Tree1
+
+let tree2: Tree2;
+>tree2 : Tree2
+>Tree2 : Tree2
+
+tree1 = tree2;
+>tree1 = tree2 : Tree2
+>tree1 : Tree1
+>tree2 : Tree2
+
+tree2 = tree1;
+>tree2 = tree1 : Tree1
+>tree2 : Tree2
+>tree1 : Tree1
+