QGuiApplication crashed when passing Unicode string like Thai parameter?

[dhuta]

I have a gui app, which want to grab an image of QQuickView, though gui app, i want to control it in terminal. At the same time, the only component in qml passed to QQuickView is just a Text component . I want to pass my wantted string to the Text's text property. But, i find it probably crash when i pass in some unicode string like Thai. My OS is win7, Qt5.3.1. The app crashs in QCoreApplication::arguments(). Or the demand is rediculous?

How to solve it? Anyone can help me?

[SGaist]

Hi,

Can you reproduce that with a minimal compilable example ? What is the string that makes your application crash ?

[dhuta]

@SGaist Sample code is at https://github.com/EightFingerDhuta/qt/tree/master/crashArgs。
Test string is "สวัสดี" in thai. But it will be ok when pass "你好" etc.

This simplified sample runs ok in qtcreator (parameter passed in qtcreator), but fails when run it in cmd terminal after deploy it.

In fact, my original app even cannot run in qtcreator. When delete all build files manually and rebuild it, it can run successfully only once.

[ileonte]

@dhuta your app is crashing because argv0 is not terminated by a NULL pointer. You need to declare it as char *argv0[argc0 + 1] and then add argv0[i] = NULL; after the for loop in which you copy from argv to argv0.

[dhuta]

@ileonte It really a bug. But the sample code still failed when i not modify these parameters or add the NULL pointer as you said.

[ileonte]

@dhuta what I meant to say is add argv0[argc + 2] = NULL;. That part about argv0[i] = NULL; is wrong. Your code should look like this:

    int argc0 = argc + 2;
    char *argv0[argc0 + 1];

    for (int i = 0; i < argc; i++) {
        argv0[i] = argv[i];
    }

    argv0[argc] = arg1;
    argv0[argc + 1] = arg2;
    argv0[argc + 2] = NULL;

[dhuta]

@ileonte Yeah. I just add it exactly as you do. But the sample still crash.

[ileonte]

@dhuta Where is the call stack for the crash originating from ? Is it the QApplication constructor or the parser.process(app); call ? Also can you please push the modified code to GitHub so I can have another look ?

[dhuta]

@ileonte I have already push the modified code. When i run it under debug mode, it crashs with a message: ASSERT: "allArguments.size() == origArgc" in file kernel\qtcoreapplication.cpp line 2191. I google it, it seems that this is an already known bug: https://bugreports.qt.io/browse/QTBUG-30330. Maybe i should found another way to get my wanted result.

Thanks a lot !

[ileonte]

@dhuta That bug is marked as closed, maybe you could try updating to a newer version of Qt.

[dhuta]

@ileonte Uh, i must use Qt5.3.1, coz our project demands this version....I think i have to read file to get target text string.

Anyway, thank you~ :)