Merge pull request #358 from Icinga:fix/compare_function_windows2012r2

Fix: Compare function in Windows 2012 R2

Author: LordHepipud

doc/31-Changelog.md

@@ -13,6 +13,7 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 
 ### Bugfixes
 
+* [#300](https://github.com/Icinga/icinga-powershell-framework/issues/300) Fixes an issue on `Boolean` to empty `String` conversion for possible maximum values on check plugins on Windows 2012 R2
 * [#311](https://github.com/Icinga/icinga-powershell-framework/issues/311) Fixes an issue with negative inputs on some scenarios which will cause an exception for checks instead of continuing executing them properly
 * [#317](https://github.com/Icinga/icinga-powershell-framework/pull/317) Fixes certain file names being too long, causing errors on deploying branches
 * [#326](https://github.com/Icinga/icinga-powershell-framework/pull/326) Fixes import for module files, by using the full path to the module now instead of the name only, as files could be placed inside a folder which is not listed inside the `$ENV:PSModulePath`

lib/icinga/plugin/New-IcingaCheck.psm1

@@ -206,7 +206,7 @@ function New-IcingaCheck()
                 $this.Maximum = $this.__ThresholdObject.BaseValue;
             }
 
-            if ($this.Value -gt $this.Maximum -And [string]::IsNullOrEmpty($this.Maximum) -eq $FALSE) {
+            if ([string]::IsNullOrEmpty($this.Maximum) -eq $FALSE -And (Test-Numeric $this.Maximum) -And (Test-Numeric $this.Value) -And $this.Value -gt $this.Maximum) {
                 $this.Maximum = $this.__ThresholdObject.RawValue;
             }
         }