Initial XDG support and folder default changes

Conflicts:
	src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHost.cs

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHost.cs

@@ -185,14 +185,18 @@ namespace Microsoft.PowerShell
                 {
                     profileDir = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData) +
                         @"\Microsoft\Windows\PowerShell";
-                } else
+                } 
+                
+                else
                 {
-                    profileDir = System.IO.Path.Combine(Environment.GetEnvironmentVariable("HOME"), ".powershell");
+                    //check if the user has set an XDG path in their environment variables
+                    profileDir = Platform.SelectProductNameForDirectory("profile");                  
                 }
-
-                if (!Directory.Exists(profileDir))
+   
+                if (!Directory.Exists(profileDir)) //xdg value may have been set but not a valid directory 
                 {
-                    Directory.CreateDirectory(profileDir);
+                    Console.WriteLine("The selected directory for the profile does not exist. Using the default path.");
+                    profileDir = Platform.SelectProductNameForDirectory("default");
                 }
                 ClrFacade.SetProfileOptimizationRoot(profileDir);
             }
@@ -268,7 +272,6 @@ namespace Microsoft.PowerShell
                             : "StartupProfileData-NonInteractive");
                     exitCode = theConsoleHost.Run(cpp, !string.IsNullOrEmpty(preStartWarning));
                 }
-
             }
             finally
             {

src/Microsoft.PowerShell.PSReadLine/Cmdlets.cs

@@ -178,14 +178,25 @@ namespace Microsoft.PowerShell
             }
             else
             {
+                //PSReadline does not have access to Utils.CorePSPlatform. Must set PSReadline path seperately                
+                string modulepath = System.Environment.GetEnvironmentVariable("XDG_CACHE_HOME");
+               
+                if (String.IsNullOrEmpty(modulepath))
+                {
+                        modulepath = System.IO.Path.Combine(
+                                                             Environment.GetEnvironmentVariable("HOME"), 
+                                                             ".config/powershell/modules");
+                }
+                        
                 HistorySavePath = System.IO.Path.Combine(
                                                          Environment.GetEnvironmentVariable("HOME"), 
-                                                         ".powershell",
+                                                         modulepath,
                                                          "PSReadLine",
                                                          hostName + "_history.txt");
-            }
-#else
-            HistorySavePath = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
+                            
+                }
+    #else
+                HistorySavePath = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
                 + @"\Microsoft\Windows\PowerShell\PSReadline\" + hostName + "_history.txt";
 #endif
             CommandValidationHandler = null;
@@ -205,7 +216,7 @@ namespace Microsoft.PowerShell
                 "Where-Object", "?", "where",
             };
         }
-
+        
         public EditMode EditMode { get; set; }
 
         public string ContinuationPrompt { get; set; }

src/System.Management.Automation/CoreCLR/CorePsPlatform.cs

@@ -96,8 +96,57 @@ namespace System.Management.Automation
                 "WSMan.format.ps1xml"
             };
 
-        // directory location of PowerShell for profile loading
-        public static string ProductNameForDirectory = ".powershell";
+        // function for choosing directory location of PowerShell for profile loading 
+        public static string SelectProductNameForDirectory (string dir){
+
+            string xdgconfighome = System.Environment.GetEnvironmentVariable("XDG_CONFIG_HOME");
+            string xdgdatahome = System.Environment.GetEnvironmentVariable("XDG_DATA_HOME"); 
+            string xdgcachehome = System.Environment.GetEnvironmentVariable("XDG_CACHE_HOME");
+            
+            
+            //the user has set XDG_CONFIG_HOME corrresponding to profile path
+            if (!String.IsNullOrEmpty(xdgconfighome) && dir == "profile")
+            {
+                return xdgconfighome;         
+            } 
+            
+            //the user has set XDG_DATA_HOME corresponding to module path 
+            if (!String.IsNullOrEmpty(xdgdatahome) && dir == "modules")
+            {
+                return xdgdatahome; 
+            }
+            
+            //the user has set XDG_CACHE_HOME
+            if (!String.IsNullOrEmpty(xdgcachehome) && dir == "history")
+            {
+                return xdgcachehome; 
+            }
+            
+            if (dir == "default")
+            {
+                return @".config/powershell"; 
+            }
+            //the user has set XDG_DATA_HOME
+            else //xdg values have not been set 
+            {
+                if (dir == "profile" || dir == "history")
+                {
+                    return @".config/powershell"; //default on Linux
+                } 
+                if (dir == "modules")
+                {
+                    if (!Directory.Exists(@".config/powershell/modules"))
+                    {                        
+                        Directory.CreateDirectory(@".config/powershell/modules");
+                           
+                    }
+                    
+                    return @".config/powershell/modules"; //default on Linux
+                }
+                
+                return @".config/powershell";
+            }
+        }
 
         // ComObjectType is null on CoreCLR for Linux since there is
         // no COM support on Linux

src/System.Management.Automation/engine/Modules/ModuleIntrinsics.cs

@@ -548,12 +548,7 @@ namespace System.Management.Automation
         /// <returns>personal module path</returns>
         internal static string GetPersonalModulePath()
         {
-            string personalModuleRoot = Path.Combine(
-                    Path.Combine(
-                        Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments),
-                            Utils.ProductNameForDirectory),
-                    Utils.ModuleDirectory);
-
+            string personalModuleRoot = Platform.SelectProductNameForDirectory("modules");
             return personalModuleRoot;
         }
 
@@ -597,6 +592,7 @@ namespace System.Management.Automation
                     psHome = psHome.ToLowerInvariant().Replace("\\syswow64\\", "\\system32\\");
                 }
                 Interlocked.CompareExchange(ref SystemWideModulePath, Path.Combine(psHome, Utils.ModuleDirectory), null);
+                   
             }
 
             return SystemWideModulePath;

src/System.Management.Automation/engine/Utils.cs

@@ -606,13 +606,13 @@ namespace System.Management.Automation
         /// Profile uses this to control profile loading.
         /// </remarks>
         internal static string ProductNameForDirectory =
-            Platform.IsWindows ? "WindowsPowerShell" : Platform.ProductNameForDirectory;
+            Platform.IsWindows ? "WindowsPowerShell" : Platform.SelectProductNameForDirectory("profile");
 
         /// <summary>
         /// The name of the subdirectory that contains packages.
         /// </summary>
         internal static string ModuleDirectory = "Modules";
-
+        
         /// <summary>
         /// The partial path to the DSC module directory
         /// </summary>

src/System.Management.Automation/engine/hostifaces/HostUtilities.cs

@@ -152,6 +152,7 @@ namespace System.Management.Automation
                 {
                     continue;
                 }
+
                 command = new PSCommand();
                 command.AddCommand(profilePath, false);
                 commands.Add(command);
@@ -186,7 +187,14 @@ namespace System.Management.Automation
             {
                 basePath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
                 basePath = IO.Path.Combine(basePath, Utils.ProductNameForDirectory);
+                
+                //If the profile path doesn't exist, create it.
+                if (!System.IO.Directory.Exists(basePath))
+                {
+                    System.IO.Directory.CreateDirectory(basePath);
+                }
             }
+        
             else
             {
                 basePath = GetAllUsersFolderPath(shellId);
@@ -198,7 +206,6 @@ namespace System.Management.Automation
 
             string profileName = useTestProfile ? "profile_test.ps1" : "profile.ps1";
 
-
             if (!string.IsNullOrEmpty(shellId))
             {
                 profileName = shellId + "_" + profileName;