> On Sept. 28, 2015, 7:02 a.m., Marcus Meissner wrote:
> > according to git blame I added this to help autoload the camera list ... 
> > although I have not much recall of this :/

A run of 'gdb systemsettings5' with 'break KKameraConfig::load()' and 
corresponding calls to 'bt' informs me that with the load() call inside 
displayGPSuccessDialogue, first it is called by the displayGPSuccessDialogue:
``` 
#0  KKameraConfig::load (this=0x9d3310) at 
/home/christian/kde-git/Extras/kamera/kcontrol/kamera.cpp:203
#1  0x00007fffd3e08bec in KKameraConfig::displayGPSuccessDialogue 
(this=0x9d3310)
    at /home/christian/kde-git/Extras/kamera/kcontrol/kamera.cpp:171
#2  0x00007fffd3e07c04 in KKameraConfig::KKameraConfig (this=0x9d3310, 
parent=0x9c3240)
    at /home/christian/kde-git/Extras/kamera/kcontrol/kamera.cpp:67
#3  0x00007fffd3e0c89e in KPluginFactory::createInstance<KKameraConfig, 
QWidget> (parentWidget=0x0, parent=0x9c3240, args=...)
    at /opt/kde/include/KF5/KCoreAddons/kpluginfactory.h:477
#4  0x00007ffff34df827 in KPluginFactory::create(char const*, QWidget*, 
QObject*, QList<QVariant> const&, QString const&) ()
   from /opt/kde/lib64/libKF5CoreAddons.so.5
#5  0x00007ffff798ed10 in KCModuleLoader::loadModule(KCModuleInfo const&, 
KCModuleLoader::ErrorReporting, QWidget*, QStringList const&) () from 
/opt/kde/lib64/libKF5KCMUtils.so.5
#6  0x00007ffff799785c in KCModuleProxyPrivate::loadModule() () from 
/opt/kde/lib64/libKF5KCMUtils.so.5
...
#67 0x00.... in main ()
```

and then again by KCModule::qt_static_metacall:
```
#0  KKameraConfig::load (this=0x9d3310) at 
/home/christian/kde-git/Extras/kamera/kcontrol/kamera.cpp:203
#1  0x00007ffff6a4e9d9 in KCModule::qt_static_metacall(QObject*, 
QMetaObject::Call, int, void**) ()
   from /opt/kde/lib64/libKF5ConfigWidgets.so.5
#2  0x00007ffff3075832 in QObject::event(QEvent*) () from 
/opt/qt5/lib64/libQt5Core.so.5
#3  0x00007ffff4be74c7 in QWidget::event(QEvent*) () from 
/opt/qt5/lib64/libQt5Widgets.so.5
#4  0x00007ffff4ba699c in QApplicationPrivate::notify_helper(QObject*, QEvent*) 
() from /opt/qt5/lib64/libQt5Widgets.so.5
#5  0x00007ffff4babb40 in QApplication::notify(QObject*, QEvent*) () from 
/opt/qt5/lib64/libQt5Widgets.so.5
#6  0x00007ffff3046ae3 in QCoreApplication::notifyInternal(QObject*, QEvent*) 
() from /opt/qt5/lib64/libQt5Core.so.5
#7  0x00007ffff3048d53 in QCoreApplicationPrivate::sendPostedEvents(QObject*, 
int, QThreadData*) ()
   from /opt/qt5/lib64/libQt5Core.so.5
#8  0x00007ffff309bac3 in ?? () from /opt/qt5/lib64/libQt5Core.so.5
#9  0x00007fffed7b778d in g_main_dispatch (context=0x7fffdc0016f0) at 
../../glib/gmain.c:3122
#10 g_main_context_dispatch (context=context@entry=0x7fffdc0016f0) at 
../../glib/gmain.c:3737
#11 0x00007fffed7b7a38 in g_main_context_iterate 
(context=context@entry=0x7fffdc0016f0, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at ../../glib/gmain.c:3808
#12 0x00007fffed7b7adc in g_main_context_iteration (context=0x7fffdc0016f0, 
may_block=1) at ../../glib/gmain.c:3869
#13 0x00007ffff309beb7 in 
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /opt/qt5/lib64/libQt5Core.so.5
#14 0x00007ffff3044682 in 
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from 
/opt/qt5/lib64/libQt5Core.so.5
#15 0x00007ffff304c18d in QCoreApplication::exec() () from 
/opt/qt5/lib64/libQt5Core.so.5
#16 0x000000000040f108 in main ()
```

I would guess that the second call occurs immediately after (but I didn't step 
through, so I could be horribly wrong). 

load() does indeed call populateDeviceListView(), then gp_list_free(list). 
gp_list_new(&list) is called in the same function, so I don't think there's any 
risk of double free, but something strange happens.

If I watch carefully, sometimes the correct kcm loads and is then replaced by 
the scrollbars between debug statements to 'kamera.kcontrol' in 
~/.xsession-errors (these debug statements aren't in the git repository since 
they're fairly useless for general use I imagine). I'm sure the reliability of 
'tail -f' for judging timing is pretty non-existent but I find it qualitatively 
convincing.


- Christian


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/125433/#review86025
-----------------------------------------------------------


On Sept. 28, 2015, 5:09 a.m., Christian Butcher wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/125433/
> -----------------------------------------------------------
> 
> (Updated Sept. 28, 2015, 5:09 a.m.)
> 
> 
> Review request for KDE Graphics and Plasma.
> 
> 
> Repository: kamera
> 
> 
> Description
> -------
> 
> The displayGPSuccessDialogue(void) function calls load() as its last 
> statement currently.
> 
> Documentation for the KCModule api (both 
> [kde4](http://api.kde.org/4.x-api/kdelibs-apidocs/kdeui/html/classKCModule.html)
>  and 
> [frameworks](http://api.kde.org/frameworks-api/frameworks5-apidocs/kconfigwidgets/html/classKCModule.html))
>  informs the reader that load() is called at the end of construction - 
> consequently it seems that the additional load() call leads to the function 
> (which is implemented as KKameraConfig::load() ) being called twice.
> 
> [Bug 236844](https://bugs.kde.org/show_bug.cgi?id=236844) may be related but 
> at least on my KF5 based system, this does not cause or prevent a crash, 
> which is referenced in the bug.
> 
> Separately, COPYING-CMAKE-SCRIPTS is referenced by the FindGphoto2.cmake 
> file, and seems to have missed the commit in 
> [RR-125230](https://git.reviewboard.kde.org/r/125230/). If this was 
> intentional, then my apologies for readding here, but if so, the 
> FindGphoto2.cmake file will need changing in some way.
> 
> 
> Diffs
> -----
> 
>   COPYING-CMAKE-SCRIPTS PRE-CREATION 
>   kcontrol/kamera.cpp 2d8f61449a5a6f2650d864c864652ebea780a422 
>   kcontrol/kameradevice.h b0ecb974f8fcb765228afe1965aeebab8e7656ed 
> 
> Diff: https://git.reviewboard.kde.org/r/125433/diff/
> 
> 
> Testing
> -------
> 
> When the call is present, opening the Kamera KCM within systemsettings after 
> saving changes and going back to the main systemsettings view leads to a 
> strange set of scrollbars.
> 
> With the additional call removed, the KCM-Kamera opens properly on the second 
> attempt, after saving changes.
> 
> As a camera to test, the first (in the scroll list) serial port camera is 
> 'Achiever Digital Adc65'. 'Barbie' may be easier to find as the first entry 
> for 'B', and is also more memorable... I used a serial camera, since then the 
> kcm will load images even without a camera connected
> 
> 
> File Attachments
> ----------------
> 
> scrollbars
>   
> https://git.reviewboard.kde.org/media/uploaded/files/2015/09/28/74e8bd93-4c4a-4103-9fb1-7bd106258058__kcm1.png
> 
> 
> Thanks,
> 
> Christian Butcher
> 
>

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