From 8db4bef22ce0ba465e980d9e381d84f99aae31db Mon Sep 17 00:00:00 2001
From: Pawel Flajszer <45766938+pflajszer@users.noreply.github.com>
Date: Sat, 24 Jun 2023 11:17:40 +0200
Subject: [PATCH] Remove obsolete "Concat" method

This is a squashed merge of PR #1002 that closes #993.
---
 MoreLinq/Append.cs                            | 13 ---------
 MoreLinq/CompatibilitySuppressions.xml        | 28 +++++++++++++++++++
 .../PublicAPI/net6.0/PublicAPI.Unshipped.txt  |  1 +
 .../netstandard2.0/PublicAPI.Unshipped.txt    |  1 +
 .../netstandard2.1/PublicAPI.Unshipped.txt    |  1 +
 README.md                                     |  7 +++--
 6 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/MoreLinq/Append.cs b/MoreLinq/Append.cs
index e0800b364..b081bbd83 100644
--- a/MoreLinq/Append.cs
+++ b/MoreLinq/Append.cs
@@ -38,18 +38,5 @@ public static IEnumerable<T> Append<T>(this IEnumerable<T> head, T tail)
                 ? node.Concat(tail)
                 : PendNode<T>.WithSource(head).Concat(tail);
         }
-
-        /// <summary>
-        /// Returns a sequence consisting of the head elements and the given tail element.
-        /// </summary>
-        /// <typeparam name="T">Type of sequence</typeparam>
-        /// <param name="head">All elements of the head. Must not be null.</param>
-        /// <param name="tail">Tail element of the new sequence.</param>
-        /// <returns>A sequence consisting of the head elements and the given tail element.</returns>
-        /// <remarks>This operator uses deferred execution and streams its results.</remarks>
-
-        [Obsolete("Use " + nameof(Append) + " instead.")]
-        public static IEnumerable<T> Concat<T>(this IEnumerable<T> head, T tail) =>
-            head.Append(tail);
     }
 }
diff --git a/MoreLinq/CompatibilitySuppressions.xml b/MoreLinq/CompatibilitySuppressions.xml
index 1d7bf3d3e..da1602414 100644
--- a/MoreLinq/CompatibilitySuppressions.xml
+++ b/MoreLinq/CompatibilitySuppressions.xml
@@ -1,6 +1,34 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/diagnostic-ids -->
 <Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:MoreLinq.MoreEnumerable.Concat``1(System.Collections.Generic.IEnumerable{``0},``0)</Target>
+    <Left>lib/net462/MoreLinq.dll</Left>
+    <Right>lib/netstandard2.0/MoreLinq.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:MoreLinq.MoreEnumerable.Concat``1(System.Collections.Generic.IEnumerable{``0},``0)</Target>
+    <Left>lib/net6.0/MoreLinq.dll</Left>
+    <Right>lib/net6.0/MoreLinq.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:MoreLinq.MoreEnumerable.Concat``1(System.Collections.Generic.IEnumerable{``0},``0)</Target>
+    <Left>lib/netstandard2.0/MoreLinq.dll</Left>
+    <Right>lib/netstandard2.0/MoreLinq.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:MoreLinq.MoreEnumerable.Concat``1(System.Collections.Generic.IEnumerable{``0},``0)</Target>
+    <Left>lib/netstandard2.1/MoreLinq.dll</Left>
+    <Right>lib/netstandard2.1/MoreLinq.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>PKV006</DiagnosticId>
     <Target>.NETStandard,Version=v1.0</Target>
diff --git a/MoreLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt b/MoreLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt
index 7dc5c5811..b4ddb014c 100644
--- a/MoreLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt
+++ b/MoreLinq/PublicAPI/net6.0/PublicAPI.Unshipped.txt
@@ -1 +1,2 @@
 #nullable enable
+*REMOVED*static MoreLinq.MoreEnumerable.Concat<T>(this System.Collections.Generic.IEnumerable<T>! head, T tail) -> System.Collections.Generic.IEnumerable<T>!
diff --git a/MoreLinq/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt b/MoreLinq/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt
index 7dc5c5811..b4ddb014c 100644
--- a/MoreLinq/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt
+++ b/MoreLinq/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt
@@ -1 +1,2 @@
 #nullable enable
+*REMOVED*static MoreLinq.MoreEnumerable.Concat<T>(this System.Collections.Generic.IEnumerable<T>! head, T tail) -> System.Collections.Generic.IEnumerable<T>!
diff --git a/MoreLinq/PublicAPI/netstandard2.1/PublicAPI.Unshipped.txt b/MoreLinq/PublicAPI/netstandard2.1/PublicAPI.Unshipped.txt
index 7dc5c5811..b4ddb014c 100644
--- a/MoreLinq/PublicAPI/netstandard2.1/PublicAPI.Unshipped.txt
+++ b/MoreLinq/PublicAPI/netstandard2.1/PublicAPI.Unshipped.txt
@@ -1 +1,2 @@
 #nullable enable
+*REMOVED*static MoreLinq.MoreEnumerable.Concat<T>(this System.Collections.Generic.IEnumerable<T>! head, T tail) -> System.Collections.Generic.IEnumerable<T>!
diff --git a/README.md b/README.md
index ece3287fc..2c9962eda 100644
--- a/README.md
+++ b/README.md
@@ -167,8 +167,11 @@ first sequence has fewer, the same or more elements than the second sequence.
 
 Returns a sequence consisting of the head element and the given tail elements.
 
-This method is obsolete and will be removed in a future version. Use `Append`
-instead.
+This extension was rendered obsolete in version 3.0 and eventually removed in
+version 4.0. Use [`Append`][linq-append] from .NET instead that's been available
+since .NET Standard 1.6+, .NET Core 1.0+ and .NET Framework 4.7.1+.
+
+[linq-append]: https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.append
 
 ### Consume