System.Uri.AssertInvariants failing with debug assert: offset.Query == 0

[elinor-fung]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1143909
Build error leg or test failing: System.Resources.Extensions.BinaryFormat.Tests.WorkItemExecution
Pull request: #119518

System.Diagnostics.DebugProvider+DebugAssertException: offset.Query == 0
   at System.Diagnostics.DebugProvider.Fail(String message, String detailMessage) in /_/src/libraries/System.Private.CoreLib/src/System/Diagnostics/DebugProvider.cs:line 22
   at System.Diagnostics.Debug.Fail(String message, String detailMessage) in /_/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Debug.cs:line 134
   at System.Diagnostics.Debug.Assert(Boolean condition, String message, String detailMessage) in /_/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Debug.cs:line 98
   at System.Diagnostics.Debug.Assert(Boolean condition, String message) in /_/src/libraries/System.Private.CoreLib/src/System/Diagnostics/Debug.cs:line 87
   at System.Uri.AssertInvariants() in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 180
   at System.Uri.EnsureUriInfo() in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 373
   at System.Uri.ParseRemaining() in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 3250
   at System.Uri.EnsureParseRemaining() in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 383
   at System.Uri.GetComponentsHelper(UriComponents uriComponents, UriFormat uriFormat) in /_/src/libraries/System.Private.Uri/src/System/UriExt.cs:line 928
   at System.Uri.InternalGetComponents(UriComponents components, UriFormat format) in /_/src/libraries/System.Private.Uri/src/System/UriExt.cs:line 374
   at System.Uri.GetParts(UriComponents uriParts, UriFormat formatAs) in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 2707
   at System.Uri.CombineUri(Uri basePart, String relativePart, UriFormat uriFormat) in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 4708
   at System.Uri.GetCombinedString(Uri baseUri, String relativeStr, Boolean dontEscape, String& result) in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 694
   at System.Uri.ResolveHelper(Uri baseUri, Uri relativeUri, String& newUriString, Boolean& userEscaped) in /_/src/libraries/System.Private.Uri/src/System/UriExt.cs:line 882
   at System.Uri.CreateUri(Uri baseUri, String relativeUri, Boolean dontEscape) in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 559
   at System.Uri..ctor(Uri baseUri, String relativeUri) in /_/src/libraries/System.Private.Uri/src/System/Uri.cs:line 493
   at BinaryFormatTests.FormatterTests.BinaryFormatterTests.SerializableObjects()+MoveNext() in /_/src/libraries/System.Resources.Extensions/tests/BinaryFormatTests/Legacy/BinaryFormatterTestData.cs:line 722
   at System.Linq.Enumerable.<ToArray>g__EnumerableToArray|324_0[ValueTuple`2](IEnumerable`1 source) in /_/src/libraries/System.Linq/src/System/Linq/ToCollection.cs:line 37
   at System.Linq.Enumerable.ToArray[ValueTuple`2](IEnumerable`1 source) in /_/src/libraries/System.Linq/src/System/Linq/ToCollection.cs:line 24
   at BinaryFormatTests.FormatterTests.BinaryFormatterTests.RawSerializableObjects() in /_/src/libraries/System.Resources.Extensions/tests/BinaryFormatTests/Legacy/BinaryFormatterTestData.cs:line 66
   at BinaryFormatTests.FormatterTests.BinaryFormatterTests.get_SerializableObjects_MemberData() in /_/src/libraries/System.Resources.Extensions/tests/BinaryFormatTests/Legacy/BinaryFormatterTestData.cs:line 70

Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": ["offset.Query == 0", "AssertInvariants"],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1143909
Error message validated: [offset.Query == 0 AssertInvariants]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 9/10/2025 6:32:34 PM UTC

Report

Build	Definition	Test	Pull Request
1143909	dotnet/runtime	System.Resources.Extensions.BinaryFormat.Tests.WorkItemExecution	#119518

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	1	1

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[jkotas]

#119435 ?

cc @MihaZupan

[MihaZupan]

We have asserts that Query and Fragment offsets aren't populated if Flags.AllUriInfoSet isn't set (as we haven't finished parsing yet).

runtime/src/libraries/System.Private.Uri/src/System/Uri.cs

Lines 180 to 181 in 80dbb9f

	Debug.Assert(offset.Query == 0);
	Debug.Assert(offset.Fragment == 0);

The asserts have a race condition since a different thread may have done the parsing between us checking the flag and reading the offsets.
Introduced in #117287.

Might have to backport that to 10.0 as well if it creates too much CI noise.