Set FrameResponseHeaders._contentLength to null when Content-Length header is removed.

Author: Cesar Blum Silveira

src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/FrameHeaders.Generated.cs

@@ -3404,6 +3404,7 @@ protected override bool RemoveFast(string key)
                         {
                             if (((_bits & 2048L) != 0))
                             {
+                                _contentLength = null;
                                 _bits &= ~2048L;
                                 _headers._ContentLength = StringValues.Empty;
                                 return true;
@@ -3700,6 +3701,7 @@ protected override void ClearFast()
         {
             _bits = 0;
             _headers = default(HeaderReferences);
+            _contentLength = null;
             MaybeUnknown?.Clear();
         }
 
@@ -8358,6 +8360,7 @@ protected override bool RemoveFast(string key)
                         {
                             if (((_bits & 2048L) != 0))
                             {
+                                _contentLength = null;
                                 _bits &= ~2048L;
                                 _headers._ContentLength = StringValues.Empty;
                                 _headers._rawContentLength = null;
@@ -8609,6 +8612,7 @@ protected override void ClearFast()
         {
             _bits = 0;
             _headers = default(HeaderReferences);
+            _contentLength = null;
             MaybeUnknown?.Clear();
         }
 

test/Microsoft.AspNetCore.Server.KestrelTests/FrameResponseHeadersTests.cs

@@ -201,5 +201,29 @@ public void ContentLengthValueCanBeReadAsLongAfterAssigningHeader()
 
             Assert.Equal(42, headers.HeaderContentLengthValue);
         }
+
+        [Fact]
+        public void ContentLengthValueClearedWhenHeaderIsRemoved()
+        {
+            var headers = new FrameResponseHeaders();
+            headers.HeaderContentLength = "42";
+            var dictionary = (IDictionary<string, StringValues>)headers;
+
+            dictionary.Remove("Content-Length");
+
+            Assert.Equal(null, headers.HeaderContentLengthValue);
+        }
+
+        [Fact]
+        public void ContentLengthValueClearedWhenHeadersCleared()
+        {
+            var headers = new FrameResponseHeaders();
+            headers.HeaderContentLength = "42";
+            var dictionary = (IDictionary<string, StringValues>)headers;
+
+            dictionary.Clear();
+
+            Assert.Equal(null, headers.HeaderContentLengthValue);
+        }
     }
 }

tools/Microsoft.AspNetCore.Server.Kestrel.GeneratedCode/KnownHeaders.cs

@@ -361,7 +361,8 @@ protected override bool RemoveFast(string key)
                         if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase))
                         {{
                             if ({header.TestBit()})
-                            {{
+                            {{{If(header.Identifier == "ContentLength", () => $@"
+                                _contentLength = null;")}
                                 {header.ClearBit()};
                                 _headers._{header.Identifier} = StringValues.Empty;{(header.EnhancedSetter == false ? "" : $@"
                                 _headers._raw{header.Identifier} = null;")}
@@ -381,6 +382,7 @@ protected override void ClearFast()
         {{
             _bits = 0;
             _headers = default(HeaderReferences);
+            _contentLength = null;
             MaybeUnknown?.Clear();
         }}