Try to handle too long target path names which already exist

Author: levitation

Program.cs

@@ -822,7 +822,9 @@ public static async Task SaveFileModifications(string fullName, string fileData,
             {
                 await DeleteFile(otherFullName, context);
 
-                Directory.CreateDirectory(Path.GetDirectoryName(otherFullName));
+                var otherDirName = Path.GetDirectoryName(otherFullName);
+                if (!Directory.Exists(otherDirName))
+                    Directory.CreateDirectory(otherDirName);
 
                 //@"\\?\" prefix is needed for writing to long paths: https://stackoverflow.com/questions/44888844/directorynotfoundexception-when-using-long-paths-in-net-4-7
                 await FileExtensions.WriteAllTextAsync(@"\\?\" + otherFullName, fileData, context.Token);
@@ -869,7 +871,9 @@ public static async Task SaveFileModifications(string fullName, byte[] fileData,
             {
                 await DeleteFile(otherFullName, context);
 
-                Directory.CreateDirectory(Path.GetDirectoryName(otherFullName));
+                var otherDirName = Path.GetDirectoryName(otherFullName);
+                if (!Directory.Exists(otherDirName))
+                    Directory.CreateDirectory(otherDirName);
 
                 //@"\\?\" prefix is needed for writing to long paths: https://stackoverflow.com/questions/44888844/directorynotfoundexception-when-using-long-paths-in-net-4-7
                 await FileExtensions.WriteAllBytesAsync(@"\\?\" + otherFullName, fileData, context.Token);