QImageReader struggles with some paths

[JonB]

@Megamouse
What platform is this on?

[Megamouse]

It works if I get the QString from a QFileDialog, even though the QString is identical to the one i got as std::string, converted with QString::fromStdString();

[SGaist]

Hi,

How do you get the one that is a std::string ?

[Megamouse]

I'm on Windows 11.

This is the log:

QString                "C:/Users/Megamouse/Pictures/Hatsune Miku: Project DIVA F_10.png"    canRead true
QString::fromStdString "C:/Users/Megamouse/Pictures/Hatsune Miku: Project DIVA F_10.png"    canRead false

[JonB]

@Megamouse
If you are on Windows how is either of those a legal pathname? [To be clear: Windows doesn't allow : in pathnames.] I don't know about why stdString makes any difference to the result regardless.

[Megamouse]

@SGaist said in QImageReader struggles with some paths:

How do you get the one that is a std::string ?

It's also not working if the path was created as QString in the first place.
Maybe there's some hidden stuff in QString coming from QFileDialog?

The path comes from regular c++ directory scan

[SGaist]

Did you try to compare the content at the lowest level ?

[JonB]

@Megamouse
I would check again your understanding that your Windows filename contains an embedded : character.

For example, try to create such a filename yourself, from a program or Explorer or whatever.

Have a read of e.g. https://stackoverflow.com/questions/10386344/how-to-get-a-file-in-windows-with-a-colon-in-the-filename. Could the solution there be relevant to your situation, could it actually be a :-looking character which is not a :?

[Megamouse]

Yes. I just did.
Turns out the original path has a FULLWIDTH COLON, while the other one converts it to a regular colon.
The QImageReader thus can't find the file.

[JonB]

@Megamouse

Turns out the original path has a FULLWIDTH COLON, while the other one converts it to a regular colon.

...which is exactly what the stackoverflow solution talks about...