Merge pull request #889 from PowerShell/help

Fixes seg fault when Get-Help cannot find topic

src/System.Management.Automation/help/HelpNotFoundException.cs

@@ -62,7 +62,11 @@ namespace Microsoft.PowerShell.Commands
         /// </summary>
         private void CreateErrorRecord()
         {
-            _errorRecord = new ErrorRecord(new ParentContainsErrorRecordException(this), "HelpNotFound", ErrorCategory.ResourceUnavailable, null);
+            string errMessage = string.Format(HelpErrors.HelpNotFound, _helpTopic);
+
+            // Don't do ParentContainsErrorRecordException(this), as this causes recursion, and creates a 
+            // segmentation fault on Linux
+            _errorRecord = new ErrorRecord(new ParentContainsErrorRecordException(errMessage), "HelpNotFound", ErrorCategory.ResourceUnavailable, null);
             _errorRecord.ErrorDetails = new ErrorDetails(typeof(HelpNotFoundException).GetTypeInfo().Assembly, "HelpErrors", "HelpNotFound", _helpTopic);
         }