Bug 463748

Summary:	kid3-cli can't open file starting with colon
Product:	[Applications] kid3	Reporter:	Mike Jonkmans <kde>
Component:	general	Assignee:	Urs Fleisch <ufleisch>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	NOR
Version First Reported In:	3.9.x
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Mike Jonkmans 2023-01-02 20:22:01 UTC

SUMMARY
***
With kid3-cli I can not seem to open a file starting with a colon.
E.g. named ':a.mp4'.
In the GUI there is no problem with such file names.
***


STEPS TO REPRODUCE
1. touch :a.mp4 a:.mp4
2. kid3-cli :a.mp4 <&- >&-
3. kid3-cli a:.mp4 <&- >&-

OBSERVED RESULT
:a.mp4 does not exist

EXPECTED RESULT
Nothing printed

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.15.0-56-generic #62~20.04.1-Ubuntu SMP x86_64 GNU/Linux
(available in About System)
KDE Plasma Version: not available
KDE Frameworks Version: not available
Qt Version: 5.12.8

ADDITIONAL INFORMATION
Running under gnome.

Comment 1 Urs Fleisch 2023-01-03 07:22:27 UTC

Thanks for the report. I analyzed the case using gdb and found out that the problem starts when QFileInfo is used:

kid3application.cpp:
839       for (const QString& path : pathList) {
840         if (!path.isEmpty()) {
841           QFileInfo fileInfo(path);
842           if (fileCheck && !fileInfo.exists()) {

fileInfo.exists() will return false if path starts with a colon. See https://doc.qt.io/qt-6/qfileinfo.html for the explanation:

> Note: Paths starting with a colon (:) are always considered absolute, as they denote a QResource.

You can use the following workaround: Use "./:a.mp4" instead of ":a.mp4" (or use the absolute path to the file).

Comment 2 Mike Jonkmans 2023-01-03 08:51:34 UTC

(In reply to Urs Fleisch from comment #1)
> Thanks for the report.
Thanks for the swift response and the great software :)

> I analyzed the case using gdb and found out that the
> problem starts when QFileInfo is used:
> 
> kid3application.cpp:
> 839       for (const QString& path : pathList) {
> 840         if (!path.isEmpty()) {
> 841           QFileInfo fileInfo(path);
> 842           if (fileCheck && !fileInfo.exists()) {
> 
> fileInfo.exists() will return false if path starts with a colon. See
> https://doc.qt.io/qt-6/qfileinfo.html for the explanation:
> 
> > Note: Paths starting with a colon (:) are always considered absolute, as they denote a QResource.

I see, reading further, the exact 'problem' is described here: https://doc.qt.io/qt-6/resources.html#runtime-api

It would have been nice if somehow the QFileInfo.exists() method could be told to skip the resource indicators.
For instance via a flag to the exists method or via the QFileInfo constructor.
But that is out of scope here.

> You can use the following workaround: Use "./:a.mp4" instead of ":a.mp4" (or
> use the absolute path to the file).

This is a nice workaround. 
Better than what I did (link the file to a fixed name).

--
Regards, Mike

Comment 3 Urs Fleisch 2023-01-03 13:08:08 UTC

I have now implemented a fix to check for files starting with a colon and automatically prepending "./", you can find a development snapshot git20230103 at https://sourceforge.net/projects/kid3/files/kid3/development/.

Comment 4 Mike Jonkmans 2023-01-03 20:08:36 UTC

The snapshot works.
Nice fix!

I found another case though:
1. touch :a.mp4  
2. kid3-cli -c 'select :a.mp4'

Looks like the same problem.
The workaround of manually putting './' in front also works here.

Comment 5 Urs Fleisch 2023-01-04 05:59:56 UTC

Thanks for the information. I have now fixed the case for select in kid3-git20230104.

Comment 6 Mike Jonkmans 2023-01-04 08:43:21 UTC

I checked it. It works.
Thanks!

Comment 7 Urs Fleisch 2023-01-12 04:39:26 UTC

Fixed in version 3.9.3.