null-safe patches

functions/private/Invoke-WinUtilFeatureInstall.ps1

@@ -16,13 +16,20 @@ function Invoke-WinUtilFeatureInstall {
                 Write-Host "Installing $feature"
                 Enable-WindowsOptionalFeature -Online -FeatureName $feature -All -NoRestart
             } catch {
-                if ($CheckBox.Exception.Message -like "*requires elevation*") {
+                if ($_.Exception -and $_.Exception.Message -like "*requires elevation*") {
                     Write-Warning "Unable to Install $feature due to permissions. Are you running as admin?"
                     Invoke-WPFUIThread -ScriptBlock { Set-WinUtilTaskbaritem -state "Error" }
                 } else {
 
                     Write-Warning "Unable to Install $feature due to unhandled exception"
-                    Write-Warning $CheckBox.Exception.StackTrace
+                    if ($_.Exception) {
+                        if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                            Write-Warning $_.Exception.Message
+                        }
+                        if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                            Write-Warning $_.Exception.StackTrace
+                        }
+                    }
                 }
             }
         }
@@ -35,13 +42,20 @@ function Invoke-WinUtilFeatureInstall {
                 Write-Host "Running Script for $CheckBox"
                 Invoke-Command $scriptblock -ErrorAction stop
             } catch {
-                if ($CheckBox.Exception.Message -like "*requires elevation*") {
+                if ($_.Exception -and $_.Exception.Message -like "*requires elevation*") {
                     Write-Warning "Unable to Install $feature due to permissions. Are you running as admin?"
                     Invoke-WPFUIThread -ScriptBlock { Set-WinUtilTaskbaritem -state "Error" }
                 } else {
                     Invoke-WPFUIThread -ScriptBlock { Set-WinUtilTaskbaritem -state "Error" }
                     Write-Warning "Unable to Install $feature due to unhandled exception"
-                    Write-Warning $CheckBox.Exception.StackTrace
+                    if ($_.Exception) {
+                        if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                            Write-Warning $_.Exception.Message
+                        }
+                        if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                            Write-Warning $_.Exception.StackTrace
+                        }
+                    }
                 }
             }
         }

functions/private/Invoke-WinUtilISOUSB.ps1

@@ -265,4 +265,4 @@ function Invoke-WinUtilISOWriteUSB {
     }) | Out-Null
 
     $script.BeginInvoke() | Out-Null
-}
+}

functions/private/Invoke-WinUtilScript.ps1

@@ -25,20 +25,35 @@ function Invoke-WinUtilScript {
         Invoke-Command $scriptblock -ErrorAction Stop
     } catch [System.Management.Automation.CommandNotFoundException] {
         Write-Warning "The specified command was not found."
-        Write-Warning $PSItem.Exception.message
+        if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+            Write-Warning $_.Exception.Message
+        }
     } catch [System.Management.Automation.RuntimeException] {
         Write-Warning "A runtime exception occurred."
-        Write-Warning $PSItem.Exception.message
+        if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+            Write-Warning $_.Exception.Message
+        }
     } catch [System.Security.SecurityException] {
         Write-Warning "A security exception occurred."
-        Write-Warning $PSItem.Exception.message
+        if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+            Write-Warning $_.Exception.Message
+        }
     } catch [System.UnauthorizedAccessException] {
         Write-Warning "Access denied. You do not have permission to perform this operation."
-        Write-Warning $PSItem.Exception.message
+        if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+            Write-Warning $_.Exception.Message
+        }
     } catch {
         # Generic catch block to handle any other type of exception
         Write-Warning "Unable to run script for $name due to unhandled exception"
-        Write-Warning $psitem.Exception.StackTrace
+        if ($_.Exception) {
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                Write-Warning $_.Exception.StackTrace
+            }
+        }
     }
 
 }

functions/private/Set-WinUtilDNS.ps1

@@ -28,6 +28,13 @@ function Set-WinUtilDNS {
         }
     } catch {
         Write-Warning "Unable to set DNS Provider due to an unhandled exception"
-        Write-Warning $psitem.Exception.StackTrace
+        if ($_.Exception) {
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                Write-Warning $_.Exception.StackTrace
+            }
+        }
     }
 }

functions/private/Set-WinUtilRegistry.ps1

@@ -46,11 +46,22 @@ function Set-WinUtilRegistry {
     } catch [System.Security.SecurityException] {
         Write-Warning "Unable to set $Path\$Name to $Value due to a Security Exception"
     } catch [System.Management.Automation.ItemNotFoundException] {
-        Write-Warning $psitem.Exception.ErrorRecord
+        Write-Warning $_.Exception.ErrorRecord
     } catch [System.UnauthorizedAccessException] {
-       Write-Warning $psitem.Exception.Message
+       if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+           Write-Warning $_.Exception.Message
+       } else {
+           Write-Warning "Unauthorized access while setting $Path\$Name"
+       }
     } catch {
         Write-Warning "Unable to set $Name due to unhandled exception"
-        Write-Warning $psitem.Exception.StackTrace
+        if ($_.Exception) {
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                Write-Warning $_.Exception.StackTrace
+            }
+        }
     }
 }

functions/private/Set-WinUtilScheduledTask.ps1

@@ -29,14 +29,23 @@ function Set-WinUtilScheduledTask {
             Enable-ScheduledTask -TaskName $Name -ErrorAction Stop
         }
     } catch [System.Exception] {
-        if($psitem.Exception.Message -like "*The system cannot find the file specified*") {
+        if ($_.Exception -and $_.Exception.Message -like "*The system cannot find the file specified*") {
             Write-Warning "Scheduled Task $name was not Found"
         } else {
             Write-Warning "Unable to set $Name due to unhandled exception"
-            Write-Warning $psitem.Exception.Message
+            if ($_.Exception -and -not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
         }
     } catch {
         Write-Warning "Unable to run script for $name due to unhandled exception"
-        Write-Warning $psitem.Exception.StackTrace
+        if ($_.Exception) {
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                Write-Warning $_.Exception.StackTrace
+            }
+        }
     }
 }

functions/private/Set-WinUtilService.ps1

@@ -34,7 +34,14 @@ Function Set-WinUtilService {
         Write-Warning "Service $Name was not found"
     } catch {
         Write-Warning "Unable to set $Name due to unhandled exception"
-        Write-Warning $_.Exception.Message
+        if ($_.Exception) {
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.Message)) {
+                Write-Warning $_.Exception.Message
+            }
+            if (-not [string]::IsNullOrWhiteSpace($_.Exception.StackTrace)) {
+                Write-Warning $_.Exception.StackTrace
+            }
+        }
     }
 
 }