8539: Allow alias in image cropper (#9266)

Co-authored-by: Owain Williams <owaingdwilliams@gmail.com>

src/Umbraco.Core/StringExtensions.cs

@@ -22,7 +22,7 @@ namespace Umbraco.Core
     ///</summary>
     public static class StringExtensions
     {
-
+        private const char DefaultEscapedStringEscapeChar = '\\';
         private static readonly char[] ToCSharpHexDigitLower = "0123456789abcdef".ToCharArray();
         private static readonly char[] ToCSharpEscapeChars;
 
@@ -1490,5 +1490,44 @@ namespace Umbraco.Core
         /// </summary>
         public static string NullOrWhiteSpaceAsNull(this string text)
             => string.IsNullOrWhiteSpace(text) ? null : text;
+
+        /// <summary>
+        /// Splits a string with an escape character that allows for the split character to exist in a string
+        /// </summary>
+        /// <param name="value">The string to split</param>
+        /// <param name="splitChar">The character to split on</param>
+        /// <param name="escapeChar">The character which can be used to escape the character to split on</param>
+        /// <returns>The string split into substrings delimited by the split character</returns>
+        public static IEnumerable<string> EscapedSplit(this string value, char splitChar, char escapeChar = DefaultEscapedStringEscapeChar)
+        {
+            if (value == null) yield break;
+
+            var sb = new StringBuilder(value.Length);
+            var escaped = false;
+
+            foreach (var chr in value.ToCharArray())
+            {
+                if (escaped)
+                {
+                    escaped = false;
+                    sb.Append(chr);
+                }
+                else if (chr == splitChar)
+                {
+                    yield return sb.ToString();
+                    sb.Clear();
+                }
+                else if (chr == escapeChar)
+                {
+                    escaped = true;
+                }
+                else
+                {
+                    sb.Append(chr);
+                }
+            }
+
+            yield return sb.ToString();
+        }
     }
 }

src/Umbraco.Web.UI.Client/src/common/services/umbrequesthelper.service.js

@@ -252,10 +252,10 @@ function umbRequestHelper($http, $q, notificationsService, eventsService, formHe
                         //each item has a property alias and the file object, we'll ensure that the alias is suffixed to the key
                         // so we know which property it belongs to on the server side
                         var file = args.files[f];
-                        var fileKey = "file_" + file.alias + "_" + (file.culture ? file.culture : "") + "_" + (file.segment ? file.segment : "");
+                        var fileKey = "file_" + (file.alias || '').replace(/_/g, '\\_') + "_" + (file.culture ? file.culture.replace(/_/g, '\\_') : "") + "_" + (file.segment ? file.segment.replace(/_/g, '\\_') : "");
 
                         if (Utilities.isArray(file.metaData) && file.metaData.length > 0) {
-                            fileKey += ("_" + file.metaData.join("_"));
+                            fileKey += ("_" + _.map(file.metaData, x => ('' + x).replace(/_/g, '\\_')).join("_"));
                         }
                         formData.append(fileKey, file.file);
                     }

src/Umbraco.Web/Editors/Binders/ContentModelBinderHelper.cs

@@ -1,5 +1,9 @@
-using System.Net;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
 using System.Net.Http;
+using System.Text;
+using System.Text.RegularExpressions;
 using System.Web.Http;
 using System.Web.Http.Controllers;
 using Umbraco.Core;
@@ -17,6 +21,8 @@ namespace Umbraco.Web.Editors.Binders
     /// </summary>
     internal static class ContentModelBinderHelper
     {
+        private const char _escapeChar = '\\';
+
         public static TModelSave BindModelFromMultipartRequest<TModelSave>(HttpActionContext actionContext, ModelBindingContext bindingContext)
             where TModelSave : IHaveUploadedFiles
         {
@@ -30,6 +36,7 @@ namespace Umbraco.Web.Editors.Binders
                 //The name that has been assigned in JS has 2 or more parts. The second part indicates the property id
                 // for which the file belongs, the remaining parts are just metadata that can be used by the property editor.
                 var parts = file.Headers.ContentDisposition.Name.Trim(Constants.CharArrays.DoubleQuote).Split(Constants.CharArrays.Underscore);
+
                 if (parts.Length < 2)
                 {
                     var response = actionContext.Request.CreateResponse(HttpStatusCode.BadRequest);