ViaHeaderValue throws on TryParse #72677
Description
var headers = new HttpResponseMessage().Headers;
headers.TryAddWithoutValidation("Via", "1.1 foo.bar, foo");
foreach (var h in headers) { } // ThrowsSystem.ArgumentException: The value cannot be null or empty. (Parameter 'protocolVersion')
at System.Net.Http.Headers.HeaderUtilities.CheckValidToken(String value, String parameterName)
at System.Net.Http.Headers.ViaHeaderValue..ctor(String protocolVersion, String receivedBy, String protocolName, String comment)
at System.Net.Http.Headers.ViaHeaderValue.GetViaLength(String input, Int32 startIndex, Object& parsedValue)
at System.Net.Http.Headers.GenericHeaderParser.GetParsedValueLength(String value, Int32 startIndex, Object storeValue, Object& parsedValue)
at System.Net.Http.Headers.BaseHeaderParser.TryParseValue(String value, Object storeValue, Int32& index, Object& parsedValue)
at System.Net.Http.Headers.HttpHeaders.TryParseAndAddRawHeaderValue(HeaderDescriptor descriptor, HeaderStoreItemInfo info, String value, Boolean addWhenInvalid)
at System.Net.Http.Headers.HttpHeaders.ParseSingleRawHeaderValue(HeaderDescriptor descriptor, HeaderStoreItemInfo info)
at System.Net.Http.Headers.HttpHeaders.ParseRawHeaderValues(HeaderDescriptor descriptor, HeaderStoreItemInfo info, Boolean removeEmptyHeader)
at System.Net.Http.Headers.HttpHeaders.GetEnumeratorCore()+MoveNext()
TryParse should never throw. In this case, it throws from the ViaHeaderValue ctor as the protocolVersion was not parsed. I assume this debug assert would trigger here as well.
This would silently succeed without throwing (but still storing a null value) before 5.0 (#47205).