Been using Gimp for years on Windows. Have also use on Linux laptop (Mint) and never noticed this problem before but only an occasional user on Linux.

Now I've moved over on the desktop to Mint and Gimp is the ONLY program that exhibits this behaviour. So, looking to find out why and if there's a setting that I can make to change this.

So, If I save a file or Export a file and the original file is called something like "Parking Location xyz" the save or export dialogues show the filename as "Parking%20Location%20xyz" and sure enough when it's saved, the file has that name - with the additional characters representing escaped spaces as part of the file name.

Not sure if this is the OS causing this or Gimp itself. Given that no other program I use (Inkscape, Libreoffice, text editors etc) do this I am assuming that it's something to do with how GIMP integrates with Mint.

Using GIMP from the Mint repository which is 2.10.36 and Mint 22.3 Cinnamon.

Any ideas?

Linux user for 25 years. I don't have spaces in filenames. For example 'Parking Location xyz' would be 'ParkingLocation-xyz'. I often use a hyphen or an underscore to separate letters or numbers. My system is a lot happier. Computers do so much for me that I'm willing to meet them halfway

I agree! It seems t me that ONLY windows allows spaces in file names. But don't use ? LOL

My Linux Mint does not do that.
Not with GIMP 2.10 or any other version.
@OP: you might need to check your language settings (there is a "control center" with a language settings item) That's where I would look.
The reason why it's "only GIMP" could be that you probably don't have another software that's so old.
GIMP 2.10 is based on Gtk2 which is dead since a few years.

Thanks all. For some reason notifications weren't working so I only just cam by, re-seeking a solution.

To anyone suggesting don't use spaces, that's no help whatsoever because I'm not about to rename terabytes of files and this isn't a question around how to name files, it's how to get a specific program to not replace " " with %20.

Since my last visit I've tried asking about this in a few Mintish areas and pretty much the same response - can't think of anything.

At one point I thought it might be because I was using FUSE to access remote shares but that's not it as I have in between moved over to mounting network shares in FStab (mainly because network throughput improves dramatically over FUSE mounted ones).

About the only thing I can think of is that there's something going on with it as a networked resource and I will look through the file server permission and user type screens but the problem is I don't get this in either my old Windows system or a laptop that uses Mint and both log into the NAS with the same user ID so the result should be the same if it were that.

quietreader, I looked at the language settings but they are all correct and there's only 3 - language, region and date/time all UK English with apply system locale system wide.
I tried downloading the 3.2 appimage from GIMP (I prefer repository software hence the 2.10 for now and looks like no more support other than appimage) but it behaves identically so it's not the version per se.

Are there any config files I can backup and delete and re-create? just in case?

Scratching around at this point but my workaround is to have a nemo window open and copy/paste the filename into the GIMP file dialogues. Editing each when there are several spaces is tedious and error prone so I don't want to carry on like this.

Only other thing I have noticed is that filename is set on file read - the window name, which is based on the filename, contains all the %20 substitutions. I assume the same source is used for all output file operations.

Any more ideas?

OK, tried as you suggested but the results weren't quite what I expected.

Backed up profile & deleted.
Started up GIMP 2.10
Def. 2.10 and profile must have been changed as I was in default dark mode, which I can't use normally.
Went to recent and there was the list of recent files, including all the %20 characters...
Opened one and sure enough tried to save that way.
Came out, deleted the profile again. Moved the backup away so it really couldn't be guessed at or located as not on the same drive.
Fired up GIMP, same result with recent - but didn't open any.
Opened from a file location and the file opened OK and the spaces were NOT substituted so export was fine in dialogue box.

So...
It looks like my original problem is linked to the profile, now I just need to work out what & how to correct the original profile because that's got a few changes in it (and I'd like to know)

However where does the list of recent files come from?? It's not in the /bin directory, nor can I see anything obviously named. Does Mint/Ununtu have a unified recent files mechanism??

More later, but if anyone has an inkling which file in the profile folder...

I asked "why are spaces in linux filenames represented by '%20"?

Why %20 Exists
• URL Compatibility: The Internet Engineering Task Force (IETF) mandates that Uniform Resource Locators (URLs) cannot contain blank spaces, as spaces act as separators in network protocols.

The Math: In the ASCII character encoding standard, a blank space is character number 32. When you convert 32 into hexadecimal (base-16), it becomes 20. The percent sign (%) tells the software that a hexadecimal code follows

How Linux Actually Handles Spaces
Because Linux allows actual spaces, the command-line interpreter (the shell) uses spaces to separate commands from arguments. To work with a file that has literal spaces in the terminal without it breaking, you must tell the shell to ignore the space's normal separating behavior:

Using Quotes: Surround the name in quotes, such as cat "My Report.pdf".

Using an Escape Character: Insert a backslash (\) before the space, such as cat My\ Report.pdf

For me Gimp opens any file with spaces in the title. I use Debian with a Gimp AppImage.

Try looking here:
~/.local/share/recently-used.xbel

It is worth looking into ~/.local/share All sorts of files that grow to large size. As teapot, the *.xbel and *.xbel.bak are the obvious but not so obvious, say, if you use okular, that keeps a list of documents. I run a little bash script to tidy up.
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However, If you have files with unwanted characters in the file name, you can export your open files using Batcher and set up a filter for the file name.
[replace, [image name], [%20], [-] ] for example replaces any %20 with a -