Breaking change to passing multiple properties as /p:P1=V1;P2=V2

[nguerrera]

I believe this was changed by dotnet/cli#9153

Steps to reproduce

1. Create test.proj with the following content

<Project>
  <Target Name="Build">
    <Message Importance="High" Text="A: $(A)" />
    <Message Importance="High" Text="B: $(B)" />
  </Target>
</Project>

2. dotnet build test.proj /p:A=1;B=2 /nologo /clp:NoSummary

Expected behavior

  A: 1
  B: 2

Actual behavior

  A: 1;B=2
  B:

Environment data

.NET Core SDK (reflecting any global.json):
 Version:   2.2.100-preview1-008941
 Commit:    dae5099ffb

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17134
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   d:\src\s\sdk\.dotnet\sdk\2.2.100-preview1-008941\

Host (useful for support):
  Version: 2.1.0-rtm-26515-03
  Commit:  caa7b7e2ba

.NET Core SDKs installed:
  2.2.100-preview1-008941 [d:\src\s\sdk\.dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.0-rtm-30752 [d:\src\s\sdk\.dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.0-rtm-30752 [d:\src\s\sdk\.dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 1.0.5 [d:\src\s\sdk\.dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.2 [d:\src\s\sdk\.dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.0 [d:\src\s\sdk\.dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.0-rtm-26515-03 [d:\src\s\sdk\.dotnet\shared\Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

[nguerrera]

cc @peterhuene

[peterhuene]

Sigh. I didn't know MSBuild supported that. We may need a fix to the command line parser that enables us to know if the original command line argument was quoted or not. Otherwise, I don't know how we can fix this to support both uses (unquoted, a delimiter for multiple properties; quoted, a literal semicolon).

[nguerrera]

cc @rainersigwald

[rainersigwald]

I don't think it can be fixed. On Windows/full framework, MSBuild inspects the raw command line string and handles quoting itself to get the intuitive behavior (/p:Foo="bar;baz" /p:Bat=z;Pow=q results in 3 properties). But that's not possible in unix-likes where the quoting is handled by the shell and the program only has access to an argument array.

[rainersigwald]

Discussion at dotnet/msbuild#471.

[peterhuene]

Ah, I see the crux of the problem then. If MSBuild decided on option 4, then I'd be in favor of reverting dotnet/cli#9153 and ask users to do the same for dotnet (escape quotes around the property value) and to not try anything fancy from our side.

[rainersigwald]

I'm ready to commit to that. I think it's the least-bad option. @AndyGerlicher objections?

[AndyGerlicher]

Seems reasonable given no good options.

[peterhuene]

Ok, I'll revert and then comment on the CLI issue to let users know. Thanks everyone!

[peterhuene]

Fixed with dotnet/cli#9394.