Cleanup BootFailedException

src/Umbraco.Core/Exceptions/BootFailedException.cs

@@ -1,9 +1,10 @@
 using System;
+using System.Text;
 
 namespace Umbraco.Core.Exceptions
 {
     /// <summary>
-    /// An exception that is thrown if the Umbraco application cannnot boot.
+    /// An exception that is thrown if the Umbraco application cannot boot.
     /// </summary>
     public class BootFailedException : Exception
     {
@@ -29,5 +30,31 @@ namespace Umbraco.Core.Exceptions
         public BootFailedException(string message, Exception inner)
             : base(message, inner)
         { }
+
+        /// <summary>
+        /// Rethrows a captured <see cref="BootFailedException"/>.
+        /// </summary>
+        /// <remarks>The exception can be null, in which case a default message is used.</remarks>
+        public static void Rethrow(BootFailedException bootFailedException)
+        {
+            if (bootFailedException == null)
+                throw new BootFailedException(DefaultMessage);
+
+            // see https://stackoverflow.com/questions/57383
+            // would that be the correct way to do it?
+            //ExceptionDispatchInfo.Capture(bootFailedException).Throw();
+
+            Exception e = bootFailedException;
+            var m = new StringBuilder();
+            m.Append(DefaultMessage);
+            while (e != null)
+            {
+                m.Append($"\n\n-> {e.GetType().FullName}: {e.Message}");
+                if (string.IsNullOrWhiteSpace(e.StackTrace) == false)
+                    m.Append($"\n{e.StackTrace}");
+                e = e.InnerException;
+            }
+            throw new BootFailedException(m.ToString());
+        }
     }
 }