From dd69b7b52469fab8737ac36d7b6f03e6936fd4b7 Mon Sep 17 00:00:00 2001
From: Sjoerd Heijligers <Sjoerdsjoerd@users.noreply.github.com>
Date: Thu, 4 May 2023 14:20:12 +0200
Subject: [PATCH 1/2] Implemented #40713

---
 .../Compiler/Core/Extensions/ISymbolExtensions.cs             | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/ISymbolExtensions.cs b/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/ISymbolExtensions.cs
index 68fa8d01fbfec..38fad72af3ed2 100644
--- a/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/ISymbolExtensions.cs
+++ b/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/ISymbolExtensions.cs
@@ -726,12 +726,12 @@ public static bool IsKind<TSymbol>(this ISymbol symbol, SymbolKind kind, [NotNul
 
         /// <summary>
         /// Returns true for symbols whose name starts with an underscore and
-        /// are optionally followed by an integer, such as '_', '_1', '_2', etc.
+        /// are optionally followed by an integer or other underscores, such as '_', '_1', '_2', '__', '___', etc.
         /// These are treated as special discard symbol names.
         /// </summary>
         public static bool IsSymbolWithSpecialDiscardName(this ISymbol symbol)
             => symbol.Name.StartsWith("_") &&
-               (symbol.Name.Length == 1 || uint.TryParse(symbol.Name[1..], out _));
+               (symbol.Name.Length == 1 || uint.TryParse(symbol.Name[1..], out _) || symbol.Name.All(n => n.Equals('_')));
 
         /// <summary>
         /// Returns <see langword="true"/>, if the symbol is marked with the <see cref="System.ObsoleteAttribute"/>.

From b65f9bb0c4c236ea44a69bb79b21a5f1722ec1d4 Mon Sep 17 00:00:00 2001
From: Sjoerdsjoerd <Sjoerdsjoerd@users.noreply.github.com>
Date: Fri, 5 May 2023 11:14:59 +0200
Subject: [PATCH 2/2] Added testcases

---
 src/Analyzers/CSharp/Tests/NamingStyles/NamingStylesTests.cs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Analyzers/CSharp/Tests/NamingStyles/NamingStylesTests.cs b/src/Analyzers/CSharp/Tests/NamingStyles/NamingStylesTests.cs
index 6961ca3793e0c..fab99c5a9ce45 100644
--- a/src/Analyzers/CSharp/Tests/NamingStyles/NamingStylesTests.cs
+++ b/src/Analyzers/CSharp/Tests/NamingStyles/NamingStylesTests.cs
@@ -1333,6 +1333,8 @@ await TestInRegularAndScriptAsync(
         [InlineData("_")]
         [InlineData("_1")]
         [InlineData("_123")]
+        [InlineData("__")]
+        [InlineData("___")]
         public async Task TestDiscardParameterAsync(string identifier)
         {
             await TestMissingInRegularAndScriptAsync(
@@ -1348,6 +1350,8 @@ void M(int [|{identifier}|])
         [InlineData("_")]
         [InlineData("_1")]
         [InlineData("_123")]
+        [InlineData("__")]
+        [InlineData("___")]
         public async Task TestDiscardLocalAsync(string identifier)
         {
             await TestMissingInRegularAndScriptAsync(