From 2ca0b935aba3933bf0f22c30dbd3f86c34057a8d Mon Sep 17 00:00:00 2001
From: Eugene Shcherbo <eugene.shcherbo@gmail.com>
Date: Wed, 14 Oct 2020 18:26:04 +0300
Subject: [PATCH] Validate input string passed to LogValuesFormatter (#43238)

Add validation of a format string passed to LogValuesFormatter
to throw `ArgumentNullException` if the string is `null`
so that all the methods of the `LogMessage.Define` group
depending on that class doesn't throw `NullReferenceException`
when configuring a logger.

Fix #36565
---
 .../src/LogValuesFormatter.cs                        |  5 +++++
 .../tests/Common/LoggerMessageTest.cs                | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/src/LogValuesFormatter.cs b/src/libraries/Microsoft.Extensions.Logging.Abstractions/src/LogValuesFormatter.cs
index 598554d..c632219 100644
--- a/src/libraries/Microsoft.Extensions.Logging.Abstractions/src/LogValuesFormatter.cs
+++ b/src/libraries/Microsoft.Extensions.Logging.Abstractions/src/LogValuesFormatter.cs
@@ -22,6 +22,11 @@ namespace Microsoft.Extensions.Logging
 
         public LogValuesFormatter(string format)
         {
+            if (format == null)
+            {
+                throw new ArgumentNullException(nameof(format));
+            }
+
             OriginalFormat = format;
 
             var sb = new StringBuilder();
diff --git a/src/libraries/Microsoft.Extensions.Logging/tests/Common/LoggerMessageTest.cs b/src/libraries/Microsoft.Extensions.Logging/tests/Common/LoggerMessageTest.cs
index 41a351b..68a42a9 100644
--- a/src/libraries/Microsoft.Extensions.Logging/tests/Common/LoggerMessageTest.cs
+++ b/src/libraries/Microsoft.Extensions.Logging/tests/Common/LoggerMessageTest.cs
@@ -322,6 +322,26 @@ namespace Microsoft.Extensions.Logging.Test
             Assert.Equal(expectedMessage, exception.Message);
         }
 
+        [Theory]
+        [MemberData(nameof(DefineMethodsData))]
+        public void DefineMessage_ThrowsException_WhenFormatString_IsNull(Func<LogLevel, EventId, string, Delegate> define)
+        {
+            // Act
+            var exception = Assert.Throws<ArgumentNullException>(
+                () => define.Invoke(LogLevel.Error, 0, null));
+        }
+
+        public static IEnumerable<object[]> DefineMethodsData => new[]
+        {
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string> },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string, string> },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string, string, string> },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string, string, string, string> },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string, string, string, string, string> },
+            new object[] { (Func<LogLevel, EventId, string, Delegate>)LoggerMessage.Define<string, string, string, string, string, string> }
+        };
+
         public static IEnumerable<object[]> LogMessagesData => new[]
         {
             new object[] { LoggerMessage.Define(LogLevel.Error, 0, "Log "), 0 },
-- 
2.7.4