Avoid re-throwing exception in bad request handling path. (#65221)

adityamandaleeka · web-flow · commit 44c0e73ca964 · 2026-01-28T11:58:10.000-08:00
diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/Http1Connection.cs b/src/Servers/Kestrel/Core/src/Internal/Http/Http1Connection.cs
@@ -735,7 +735,12 @@ protected override bool TryParseRequest(ReadResult result, out bool endConnectio
         catch (BadHttpRequestException ex)
         {
             OnBadRequest(result.Buffer, ex);
-            throw;
+
+            // Avoid re-throwing - handle the bad request state directly here
+            // to eliminate exception propagation overhead through async state machines
+            SetBadRequestState(ex);
+            endConnection = true;
+            return true;
         }
 #pragma warning restore CS0618 // Type or member is obsolete
         catch (Exception)

Original file line number	Diff line number	Diff line change
`@@ -735,7 +735,12 @@ protected override bool TryParseRequest(ReadResult result, out bool endConnectio`
`735`	`735`	`catch (BadHttpRequestException ex)`
`736`	`736`	`{`
`737`	`737`	`OnBadRequest(result.Buffer, ex);`
`738`		`- throw;`
	`738`	`+`
	`739`	`+ // Avoid re-throwing - handle the bad request state directly here`
	`740`	`+ // to eliminate exception propagation overhead through async state machines`
	`741`	`+ SetBadRequestState(ex);`
	`742`	`+ endConnection = true;`
	`743`	`+ return true;`
`739`	`744`	`}`
`740`	`745`	`#pragma warning restore CS0618 // Type or member is obsolete`
`741`	`746`	`catch (Exception)`