(GH-709) Get Exit code from PowerShell Host

When interacting with a PowerShell host, ensure it returns the proper
exit code by calling the right method that will set it for both system
powershell and the internal host.

src/chocolatey.resources/chocolatey.resources.csproj

@@ -137,6 +137,9 @@
   <ItemGroup>
     <EmbeddedResource Include="helpers\ChocolateyTabExpansion.ps1" />
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="helpers\functions\Set-PowerShellExitCode.ps1" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
        Other similar extension points exist, see Microsoft.Common.targets.

src/chocolatey.resources/helpers/functions/Set-PowerShellExitCode.ps1

@@ -0,0 +1,23 @@
+# Copyright © 2011 - Present RealDimensions Software, LLC
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# 
+# You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+Function Set-PowerShellExitCode {
+param (
+  [int]$exitCode
+)
+
+  $host.SetShouldExit($exitCode); 
+  $env:ChocolateyExitCode = $exitCode;
+}

src/chocolatey/infrastructure.app/services/PowershellService.cs

@@ -564,11 +564,11 @@ private PowerShellExecutionResults run_host(ChocolateyConfiguration config, stri
                             case PipelineState.Failed:
                             case PipelineState.Stopping:
                             case PipelineState.Stopped:
-                                host.SetShouldExit(1);
+                                if (host.ExitCode == 0) host.SetShouldExit(1);
                                 host.HostException = pipeline.PipelineStateInfo.Reason;
                                 break;
                             case PipelineState.Completed:
-                                host.SetShouldExit(0);
+                                if (host.ExitCode == -1) host.SetShouldExit(0);
                                 break;
                         }