Harden typed task parameter infrastructure

[OvesN]

Context

These issues were found while migrating real in-box tasks to typed parameters. Direct task tests passed, but real MSBuild binding, malformed inputs, logging, event forwarding, and binlog replay exposed infrastructure gaps.

Changes Made

• Malformed typed-item paths could escape as unhandled exceptions.
  TaskItem<T> derives path values from FullPath; malformed values could throw InvalidOperationException, bypassing normal parameter-binding error handling. The constructor now converts this to ArgumentException, allowing MSBuild to report MSB4030.

  Real-world reproduction:

  <GetFileHash Files="bad%00path" />

  Before the fix, binding ITaskItem<AbsolutePath>[] could terminate the node with an unhandled exception while evaluating FullPath. After the fix, the project receives:

  MSB4030: "bad path" is an invalid value for the "Files" parameter of the "GetFileHash" task.
  

• Logging of AbsolutePath task parameters could crash or inflate paths.
  ItemGroupLoggingHelper treated AbsolutePath as an arbitrary value type and called Convert.ChangeType, which throws because AbsolutePath is not IConvertible. Now we log absolute path correctly, using originally passed path in logs AbsolutePath.OriginalValue.

  Real-world reproduction:

  <VerifyFileHash File="input.txt"
                  Hash="3306EA2566F10A3C4071D8BADFB92A83D4F1D428555B4936D21C10F4F775B351" />

  With task-input logging enabled, MSBuild attempted to format the bound AbsolutePath and failed with:

  InvalidCastException: Object must implement IConvertible.
  MSB4166: Child node exited prematurely.
  

  The fixed output remains relative:

  Task Parameter:File=input.txt
  

• Forwarded task-parameter events lost relative path values.
  TaskParameterEventArgs serialized AbsolutePath through ToString(), replacing a value such as input.txt with its absolute form. Forwarding now serializes OriginalValue.

  Real-world example:

  Originating node: Task Parameter:File=input.txt
  Receiving node:   Task Parameter:File=C:\repo\input.txt
  

  A distributed logger could therefore observe a different value depending on which node produced the event. Forwarded events now retain input.txt.

• Binlog task-parameter serialization lost relative path values.
  BuildEventArgsWriter had the same ToString() behavior, so replayed binlogs differed from live output. Binlog serialization now preserves OriginalValue.

  Real-world example:

  Live build:      Task Parameter:File=input.txt
  Replayed binlog: Task Parameter:File=C:\repo\input.txt
  

  The live and replayed event streams now contain the same relative value.

Testing

Each fix has a dedicated regression test:

• FromITaskItem_InvalidPath_ThrowsArgumentException
• AbsolutePathTaskParameterTextUsesOriginalValue
• TaskParameterEventForwardingPreservesAbsolutePathOriginalValue
• BinaryLogSerializationPreservesAbsolutePathOriginalValue
• BinaryLogSerializationWritesEmptyItemSpecForDefaultAbsolutePath

All dedicated tests pass on net11.0 and net472. The full Debug build also succeeds.

Notes

This PR contains only typed-parameter infrastructure fixes. The task migrations and user documentation are in the stacked PR OvesN/msbuild#6.

[Copilot]

Pull request overview

This PR hardens MSBuild’s typed task parameter infrastructure by ensuring malformed or relative AbsolutePath values don’t crash logging/forwarding/binlog replay and that invalid typed-item paths flow through normal parameter-binding error handling.

Changes:

• Wrap FullPath metadata failures when constructing TaskItem<T> so malformed paths surface as ArgumentException (enabling MSB4030-style binding errors instead of unhandled exceptions).
• Preserve AbsolutePath.OriginalValue (relative input) when logging task parameters, forwarding TaskParameterEventArgs, and serializing task-parameter items into binlogs.
• Add regression tests covering invalid path binding, task-parameter text formatting, event forwarding, and binlog round-tripping.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Utilities.UnitTests/TaskItem_Tests.cs	Adds regression test ensuring invalid path metadata results in ArgumentException.
src/Framework/TaskParameterEventArgs.cs	Preserves AbsolutePath.OriginalValue during task-parameter event serialization.
src/Framework/TaskItem_T.cs	Converts FullPath metadata failures into ArgumentException to integrate with binding error handling.
src/Build/Logging/BinaryLogger/BuildEventArgsWriter.cs	Preserves AbsolutePath.OriginalValue when writing task-parameter item lists to binlog.
src/Build/BackEnd/Components/RequestBuilder/IntrinsicTasks/ItemGroupLoggingHelper.cs	Logs AbsolutePath parameters using OriginalValue (keeps relative input in logs).
src/Build.UnitTests/BuildEventArgsSerialization_Tests.cs	Adds regression tests for logging text, event forwarding, and binlog serialization preserving relative values.

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[baronfel]

LGTM overall - but I think we need to figure out a better pattern for the type extensibility.