Fix for issue Newly created sub-folder not shown if the parent folder…

[kmuralidaran]

… name starts with "0"

Fixes #3975

Summary

Trimming the prefix "0" from folder name creates a folder with different name compared to the user provided name and the subfolder is also not created in the user provided folder name.

Removing the code which trims the prefix "0" from folder name addresses this issue

[dnfadmin]

All CLA requirements met.

[valadas]

I am worried there was a reason for this replacement. \0 means null in a string ( see https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/strings/ ) and I believe this is there to prevent the first 0 being next to a path separator \ and thus being interpreted as a null. For instance tryting to create a folder named 0_MyFile.txt in the c:\websites\dnn\portals\1\textFiles\ folder, it would become c:\websites\dnn\portals\1\textFilesNULL_MyFile.txt.

Now stripping the 0 altogether is probably not the right solution, I wonder if we replace it with "\0" if that would work to escape the escape sequence and that would be interpreted properly on what consumes it or if maybe this hits a bump elsewhere in the same case as what we have on the old line 233...

At any rate, I think this change needs a good set of testing.

[mitchelsellers]

I second this concern

[mitchelsellers]

This item needs more review before merging, to validate usage. It appears to be only called by the file manager, but possibly could have a check done at a later time to validate that it isn't an invalid path.

BUT, the true history of WHY this was done predates GitHub so we need to further determine why.

Also - Is this used in the new file manager? if not, lets NOT change this.

[donker]

The code checks if the path contains a backslash. If it does then it checks whether it starts with "0\" (note TWO backslahses). In which case it gets cut off. Finally it checks if it starts with 0 in which case it gets cut off. It is puzzling why this is here (maybe @cnurse knows). Unfortunately the naming of the mehod or the documentation provide no clues. Very frustrating. The issue is valid though, so my vote goes to doing one round of research and then if it isn't found, we mark it as deprecated and clean up this code.

Going through various installations I cannot find a single record that has this pattern. Maybe others can do the same. SELECT * FROM dbo.Folders WHERE FolderPath LIKE '0%'. Then check those records. It must give us a hint. Maybe a specific folder provider uses this for something.

[sleupold]

I can't remember ever having a DNN website (myself or any client), where a folder started with "0".
The only idea would be the default folder for the first website, which always starts with "0" inside the website directory, but this should not be included in folder path.

[mitchelsellers]

Funny enough...DNN will create folders that start with a Zero.

Look under the /Users/ folder for an example. So it seems that code bypasses this

[sleupold]

@mitchelsellers yes, but not directly in the portal folder, i.e. the path starts with "users/0%"

[daguiler]

Hi guys.
I wonder what's so special about \0.
Yes, it's the null char, but there are dozens of other special characters that might produce similar issues, like \r, \n, \a, \b, \f, \t, etc., etc. Yet, we can create folders starting with these letters normally.

[bdukes]

Has anyone looked into whether the new asset/resource manager uses this code?

[valadas]

Hi guys.
I wonder what's so special about \0.
Yes, it's the null char, but there are dozens of other special characters that might produce similar issues, like \r, \n, \a, \b, \f, \t, etc., etc. Yet, we can create folders starting with these letters normally.

True, true... Yeah, I must admit I am a bit clueless about the purpose here...

[valadas]

Has anyone looked into whether the new asset/resource manager uses this code?

It does not directly but it calls AssetManager.Instance.CreateFolder which in turn calls this method. So I would say yeah.

[kmuralidaran]

@valadas Do we have any use case to validate the side effects of this fix?

[valadas]

@kmuralidaran Well, I am really not sure, my guess was that it was to prevent \0 which is a null escape character, but maybe it's not since other replacement characters would also be a problem here, so really not sure what is special with 0 and why this was put in place...

[bdukes]

I support this change. We allow folders that start with zero via other methods, and we have no specific scenario that is adversely affected by this change.

[mitchelsellers]

I'm with Brian on this, lets approve!

[mitchelsellers]

@valadas You good with this?

[valadas]

@valadas You good with this?

Yeah, I mean it looks it this must be a leftover from god knows what... I am approving.

[valadas]

Looks good to me