Foreground depends on a tty, results in no session password being logged

[Roxedus]

qBittorrent & operating system versions

qBittorrent: 4.6.1
Operating system: Ubuntu 20.04.5 LTS
Qt: 6.5.2-r0
libtorrent-rasterbar: info not present in SBOM

What is the problem?

This behavior has been present for a while, but has not caused any grief until 4.6.1 started logging the password in this area of the code.

The message that prints the temporary session password here does not run unless there is a tty present when it is running in the foreground, it is however shown when the application is told to shutdown (it presumably killed whatever was waiting/hanging on a tty) . The application does not show any other negative effects from running in the foreground without a tty (containers has done this for years).

Steps to reproduce

Run the official container without a tty and notice the lack of the A temporary password is provided for this session message.

docker run --rm --name=test -p 8080:8080 --tmpfs /config:exec ghcr.io/qbittorrent/docker-qbittorrent-nox:4.6.1-1

(ctrl + c starts the shutdown process, and you can now see the message getting logged)
then run the same image, but with a tty (-t) assigned.

docker run --rm -t --name=test -p 8080:8080 --tmpfs /config:exec ghcr.io/qbittorrent/docker-qbittorrent-nox:4.6.1-1

Additional context

No response

Log(s) & preferences file(s)

No response

[sledgehammer999]

@glassez @Chocobo1

[Chocobo1]

I'll take a look at it in the weekend.

[mariushosting]

Thank you @Roxedus !

[saltydk]

Turn off stdout buffering or insert a manual fflush on stdout in this section. Issue is likely that prints are no longer line buffered when there isn't an interactive device (tty).

On a related note this is the case for everything the WEB UI section prints, like this

[sledgehammer999]

@Roxedus are you able to build/test yourself?
If so can you test the following patch?

diff --git a/src/app/application.cpp b/src/app/application.cpp
index e22f2f670..38df74aac 100644
--- a/src/app/application.cpp
+++ b/src/app/application.cpp
@@ -924,6 +924,7 @@ int Application::exec()
                     + tr("The WebUI administrator password was not set. A temporary password is provided for this session: %1").arg(tempPassword) + u'\n'
                     + tr("You should set your own password in program preferences.") + u'\n';
             printf("%s", qUtf8Printable(warning));
+            fflush(stdout); // Necessary for environments (e.g. docker) where stdout is buffered
         }
 #endif // DISABLE_GUI
 #endif // DISABLE_WEBUI

[Roxedus]

Yes, this patch works. (build)

[nephaste]

Same problem with static version : https://github.com/userdocs/qbittorrent-nox-static

[Chocobo1]

I'll take a look at it in the weekend.

I have submitted a patch: #20018