Lookup plugin lang / icons folders in a case insensitive way (#11985)

* Use lowercase lang folder name for packages lang files

Use lowercase lang folder name for packages lang files to be consistent with Umbraco's casing

* Case insensitive `lang` folder lookup

* Comment grammar

* Setup lower case appl_plugin icons folder path

* Update Constants-SystemDirectories.cs

* Check both casings for the AppPluginIcons path

* Fixed spelling mistake + avoid multiple Exists checks

* Add IsCaseSensitiveFileSystem to IHostingEnvironment

* Add IsCaseSensitiveFileSystem to AspNetCoreHostingEnvironment

* Undo last changes

* Undo last changed

* Add FileSystemUtility

* Only perform second iconPath if OS is case sensitive

* Undo changes

* Undo changes

* Remove filesystem utils file

* Added HostingEnvironmentExtensions.cs

* Use IsCaseSensitiveFileSystem extension method

* Use the Umbraco.Extensions namespace

* Simplify IsCaseSensitiveFileSystem

* Better naming

* Use PluginIcons

* Remove unused using statement

* Delete HostingEnvironmentExtensions.cs

* Update IconService.cs

* Comment clarity

* Update src/Umbraco.Infrastructure/DependencyInjection/UmbracoBuilder.Services.cs

Co-authored-by: Paul Johnson <[email protected]>

Co-authored-by: Paul Johnson <[email protected]>
Co-authored-by: Michael Latouche <[email protected]>

Author: 3 people

src/Umbraco.Core/Constants-SystemDirectories.cs

@@ -1,3 +1,5 @@
+using System;
+
 namespace Umbraco.Cms.Core
 {
     public static partial class Constants
@@ -42,7 +44,11 @@ public static class SystemDirectories
             public const string Install = "~/install";
 
             public const string AppPlugins = "/App_Plugins";
-            public static string AppPluginIcons => "/Backoffice/Icons";
+
+            [Obsolete("Use PluginIcons instead")]
+            public const string AppPluginIcons = "/Backoffice/Icons";
+            public const string PluginIcons = "/backoffice/icons";
+            
             public const string CreatedPackages = "/created-packages";
 
 

src/Umbraco.Infrastructure/DependencyInjection/UmbracoBuilder.Services.cs

@@ -122,7 +122,8 @@ private static LocalizedTextServiceFileSources SourcesFactory(IServiceProvider c
             var pluginLangFolders = appPlugins.Exists == false
                 ? Enumerable.Empty<LocalizedTextServiceSupplementaryFileSource>()
                 : appPlugins.GetDirectories()
-                    .SelectMany(x => x.GetDirectories("Lang", SearchOption.AllDirectories))
+                    // Check for both Lang & lang to support case sensitive file systems.
+                    .SelectMany(x => x.GetDirectories("?ang", SearchOption.AllDirectories).Where(x => x.Name.InvariantEquals("lang")))
                     .SelectMany(x => x.GetFiles("*.xml", SearchOption.TopDirectoryOnly))
                     .Select(x => new LocalizedTextServiceSupplementaryFileSource(x, false));
 

src/Umbraco.Web.BackOffice/Services/IconService.cs

@@ -104,8 +104,18 @@ private IEnumerable<FileInfo> GetAllIconsFiles()
                 // iterate sub directories of app plugins
                 foreach (var dir in appPlugins.EnumerateDirectories())
                 {
-                    var iconPath = _hostingEnvironment.MapPathContentRoot($"{Constants.SystemDirectories.AppPlugins}/{dir.Name}{Constants.SystemDirectories.AppPluginIcons}");
-                    if (Directory.Exists(iconPath))
+                    // AppPluginIcons path was previoulsy the wrong case, so we first check for the prefered directory 
+                    // and then check the legacy directory.
+                    var iconPath = _hostingEnvironment.MapPathContentRoot($"{Constants.SystemDirectories.AppPlugins}/{dir.Name}{Constants.SystemDirectories.PluginIcons}");
+                    var iconPathExists = Directory.Exists(iconPath);
+
+                    if (!iconPathExists)
+                    {
+                        iconPath = _hostingEnvironment.MapPathContentRoot($"{Constants.SystemDirectories.AppPlugins}/{dir.Name}{Constants.SystemDirectories.AppPluginIcons}");
+                        iconPathExists = Directory.Exists(iconPath);
+                    }
+
+                    if (iconPathExists)
                     {
                         var dirIcons = new DirectoryInfo(iconPath).EnumerateFiles("*.svg", SearchOption.TopDirectoryOnly);
                         icons.UnionWith(dirIcons);