chocolateyGH-303 Install-ChocolateyPath Expands Variables in PATH, Ov…

…erwriting

Preexisting Variables

When adding a new element to PATH, Install-ChocolateyPath reads PATH
(wh ich contains expanded variables), appends the new element, and then
writes the value back to PATH. This results in PATH having its
variables overwritten with its values. Instead of reading $env:PATH to
find the current path, read it from the registry, which will retain the
PATH's original variables.

src/chocolatey.resources/helpers/functions/Install-ChocolateyPath.ps1

@@ -10,8 +10,8 @@
 # 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.
-
+# limitations under the License.
+
 function Install-ChocolateyPath {
 param(
   [string] $pathToInstall,
@@ -26,7 +26,14 @@ param(
   if (!$envPath.ToLower().Contains($pathToInstall.ToLower()))
   {
     Write-Host "PATH environment variable does not have $pathToInstall in it. Adding..."
-    $actualPath = Get-EnvironmentVariable -Name 'Path' -Scope $pathType
+
+    if ($pathType -eq [System.EnvironmentVariableTarget]::Machine) {
+      $reg = [Microsoft.Win32.Registry]::Machine.OpenSubKey("Environment", $true);
+    } else {
+      $reg = [Microsoft.Win32.Registry]::CurrentUser.OpenSubKey("Environment", $true);
+    }
+
+    $actualPath = $reg.GetValue('Path', $null, [Microsoft.Win32.RegistryValueOptions]::DoNotExpandEnvironmentNames)
 
     $statementTerminator = ";"
     #does the path end in ';'?
@@ -38,15 +45,18 @@ param(
 
     if ($pathType -eq [System.EnvironmentVariableTarget]::Machine) {
       if (Test-ProcessAdminRights) {
+        $reg.SetValue('Path', $actualPath)
         Set-EnvironmentVariable -Name 'Path' -Value $actualPath -Scope $pathType
       } else {
         $psArgs = "Install-ChocolateyPath -pathToInstall `'$originalPathToInstall`' -pathType `'$pathType`'"
         Start-ChocolateyProcessAsAdmin "$psArgs"
       }
     } else {
-      Set-EnvironmentVariable -Name 'Path' -Value $actualPath -Scope $pathType
+      $reg.SetValue('Path', $actualPath)
     }
 
+    $reg.Close()
+
     #add it to the local path as well so users will be off and running
     $envPSPath = $env:PATH
     $env:Path = $envPSPath + $statementTerminator + $pathToInstall