Qt5: Incorrect input text rendering with IME

[LouieTian0209]

Version: Linux qt5

After opening a FIF4 window and start typing in Find input with input method, both rendering and searching are behaving incorrectly.

Actual input text: 承包商
Rendering text in Find input: 承包商承包
Actual searching keyword: 承包

I've been daily driving the gtk2 version and I can confirm this issue is not present in gtk2 version.

Video demo:

simplescreenrecorder-2024-09-09_10.48.27.mp4

[Alexey-T]

Can I ask you try to reproduce it on Lazarus IDE some dialog? if you can, we can safely post the bugreport to Lazarus!
this is IDE issue, because text input in FIF4 is usual OS input (not ATSynedit).

[Alexey-T]

This can be the dialog in IDE called by "Search / Find" or "Search / Find in files".
IMPORTANT: the IDE must be recompiled with Qt5 widgetset!
To do it, call the IDE dialog "Tools / Configure Build Lazarus", and set Qt5 there:

Then press "Build" button and wait until it compiles Ide.

[LouieTian0209]

Encountering an error when compiling with qt5:

I did have libqt5pas installed already.

[Alexey-T]

It means that you missed to install libQt5pas-DEV . this is the 2nd package listed in the releases of https://github.com/davidbannon/libqt5pas/releases

libqt5pas-dev_2.15-1_amd64.deb

Does installing DEV pkg help?

[LouieTian0209]

Does installing DEV pkg help?

Yes, it helps. And I can compile it with qt5 just fine.

Tried in Search -> Find in Files dialog and this issue is indeed present!

Demo video:

simplescreenrecorder-2024-09-09_17.08.14.mp4

[Alexey-T]

good, so now we are ready to post the bugreport for Lazarus bugtracker. Please do it. attach the detailed description how to repro it in IDE, and video.
mention the Qt5 widgetset.

[LouieTian0209]

Issue created, link is here: https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/41128

[Alexey-T]

Main man related to Qt5 said it is problem of Qt5 framework. pls check the same on some non-lazarus apps build on Qt5. it may be old versions of Kate editor (newest is bassed on Qt6).

[LouieTian0209]

Main man related to Qt5 said it is problem of Qt5 framework. pls check the same on some non-lazarus apps build on Qt5. it may be old versions of Kate editor (newest is bassed on Qt6).

Tried with Clementine, which is a Qt5 application, and did not encounter this issue. I'll report back to that issue.