MySQL Bugs: #40475: my_open.c#my_open accepts space only and special characters as filenames

Bug #40475	my_open.c#my_open accepts space only and special characters as filenames
Submitted:	3 Nov 2008 9:03	Modified:	16 Feb 2009 9:15
Reporter:	Jørgen Løland	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	6.0	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
my_open can be used to create files containing of only space or special characters. For cross-platform compatibility, it should be considered whether such file names are acceptable.

The symptoms were first seen in backup, see bug#34770.

How to repeat:
For special characters:
select 5 into outfile '__**))!@#$%^&*';

For space - call my_open with space file name:
char* mystr="/tmp/ ";
m_fd= my_open(mystr, m_flags, MYF(0));

In linux, both files are created successfully.

Email from Peter G:
-------------------
Users should avoid odd characters for portability reasons,
but I'm unable to find a statement in the manual saying
"don't use these characters". And RESTORE works.

Thank you for the report.

As you noted in hidden comment there is no word in manual about having filename from only special characters is not allowed and it works. Why do you want this to be not allowed?

Regarding to spaces please indicate how user can create such a file and why it is problem.

Special characters - as Peter G says: "for compatibility".

For space-only filenames, you'll have to look at the code sample pasted above. 

If file names

'#¤%&¤.bup' and ' ' are not considered problematic, this bug report can be closed as "Won't fix".

Example compatibility problem:

When executing "backup database db to '*';"

On Linux: Creates a file named '*'
On Windows: Errors

Thank you for the feedback.

Verified as described: we should define and document if it is allowed or not.

why should it be disallowed ? perfectly valid file names.

I'm saying "For cross-platform compatibility, it should be considered whether such file names are acceptable." If cross-platform compatibility is not a concern here, feel free to close the bug.