VB.NET build event editing removes $(ProjectDir) and possibly other variables

[drewnoakes]

Visual Studio Version: Version 16.5.0 Preview 1.0 [29511.109.master]

Summary:

The editor for VB.NET build events is removing $(Property) variables.

Steps to Reproduce:

1. Create a new VB.NET (.NET Core) project
2. Project properties -> Compile -> Build Events...
3. Add pre-build event command line text of "$(ProjectDir)"
4. Click OK
5. Open project file, see <PreBuildEvent>"$(ProjectDir)"</PreBuildEvent>
6. Project properties -> Compile -> Build Events...
7. Pre-build command is shown as ""

Expected Behavior:

Command text is retained.

Actual Behavior:

Command text is broken and editing it will remove variables from the project file.

User Impact:

Potentially broken build after using editor.

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Originally reported in this ticket against 15.9. Still repros in 16.5.

[davkean]

Triage: Please check C# too.

[drewnoakes]

I verified C# when filing this issue and it doesn't have the same problem. The VB pages have different UI and logic for build events.

For C# you get...

  <Target Name="PreBuild" BeforeTargets="PreBuildEvent">
    <Exec Command="&quot;$(ProjectDir)&quot;" />
  </Target>

  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
    <Exec Command="&quot;$(ProjectDir)&quot;" />
  </Target>

...and the property round trips correctly.