If you go to file associations -> inode -> directory change the order to use dolphin.

Then in Default application Dolphin is checked and place in first position.
Look like the default application had becomed a viewer of file association.

Mostly this is linked to the introduction of MimeApps

Thanks for your response. This workaround is working for me. But nevertheless it should be possible to choose Dolphin as File Manager in standard applications.

*** Bug 359794 has been marked as a duplicate of this bug. ***

OK, in my tests it works but I have a very different environment. Can you help me debug this remotely?

Please revert to the situation where it's broken, e.g. by deleting/renaming ~/.config/mimeapps.list  and ~/.local/share/applications/mimeapps.list. Make sure it's broken again, then let's debug ;)

When you select dolphin in the control center, what gets written into ~/.config/mimeapps.list ?
What is the first offer in `ktraderclient5 --mimetype inode/directory` ?
   [I just improved that tool so that next time the output is much shorter]
What program opens if you run `kde-open5 .` in a terminal ?
If that works, what action do you use, which results in the wrong filemanager opening?

Ok, i changed the setting in file association - inode- directory back to the setting it was before (files). Like before folders are opened with nautilus now. The file ~/.config/mimeapps.list is now:

[Added Associations]
inode/directory=org.gnome.Nautilus.desktop;org.kde.dolphin.desktop;pcmanfm.desktop;kde4-kfmclient_dir.desktop;

[Default Applications]
inode/directory=org.gnome.Nautilus.desktop;


chosing Dolphin as standard application for folders changes the file as following:

[Added Associations]
inode/directory=org.kde.dolphin.desktop;org.gnome.Nautilus.desktop;pcmanfm.desktop;kde4-kfmclient_dir.desktop;

[Default Applications]
inode/directory=org.kde.dolphin.desktop;

but nevertheless folders are opened in Nautilus. The setting takes no effect. if i open KDE Control Center, the option (thats the option for Nautilus) is checked again. 

ktraderclient gives the following output:

Florian@linux-vaio:~> ktraderclient5 --mimetype inode/directory
mimetype is : inode/directory
got 9 offers.
---- Offer 0 ----
Request for unknown property "DBusActivatable"
Invalid property DBusActivatable
StartupNotify : 'TRUE'
Request for unknown property "X-GNOME-Bugzilla-Bugzilla"
Invalid property X-GNOME-Bugzilla-Bugzilla
Request for unknown property "X-GNOME-Bugzilla-Component"
Invalid property X-GNOME-Bugzilla-Component
Request for unknown property "X-GNOME-Bugzilla-Product"
Invalid property X-GNOME-Bugzilla-Product
Request for unknown property "X-GNOME-Bugzilla-Version"
Invalid property X-GNOME-Bugzilla-Version
Request for unknown property "X-GNOME-UsesNotifications"
Invalid property X-GNOME-UsesNotifications
Request for unknown property "X-SuSE-translate"
Invalid property X-SuSE-translate
Type : 'Application'
Name : 'Dateien'
Comment : 'Auf Dateien zugreifen und diese organisieren'
Invalid property GenericName
Icon : 'system-file-manager'
Exec : 'nautilus --new-window %U'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - application/x-gnome-saved-search - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/org.gnome.Nautilus.desktop'
DesktopEntryName : 'org.gnome.nautilus'
Keywords : 'Ordner - Verwaltung - Laufwerk - Festplatte - Dateisystem - Dateien'
FormFactors : ''
Categories : 'GNOME - GTK - Utility - Core - FileManager'
---- Offer 1 ----
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
X-DBUS-ServiceName : 'org.kde.dolphin'
X-DocPath : 'dolphin/index.html'
Type : 'Application'
Name : 'Dolphin'
Invalid property Comment
GenericName : 'Dateiverwaltung'
Icon : 'system-file-manager'
Exec : 'dolphin %u'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '10'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/org.kde.dolphin.desktop'
DesktopEntryName : 'org.kde.dolphin'
Keywords : ''
FormFactors : ''
Categories : 'Qt - KDE - System - FileManager'
---- Offer 2 ----
StartupNotify : 'TRUE'
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
Request for unknown property "X-SuSE-translate"
Invalid property X-SuSE-translate
Type : 'Application'
Name : 'PCManFM Dateimanager'
Comment : 'Das Dateisystem durchsuchen und Dateien verwalten'
GenericName : 'Dateimanager'
Icon : 'system-file-manager'
Exec : 'pcmanfm %U'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/pcmanfm.desktop'
DesktopEntryName : 'pcmanfm'
Keywords : ''
FormFactors : ''
Categories : 'System - FileManager - Utility - Core - GTK - Application - System'
---- Offer 3 ----
NoDisplay : 'TRUE'
Type : 'Application'
Name : 'Konqueror'
Invalid property Comment
Invalid property GenericName
Icon : 'konqueror'
Exec : 'kfmclient openURL %u inode/directory'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '9'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/kde4/kfmclient_dir.desktop'
DesktopEntryName : 'kfmclient_dir'
Keywords : ''
FormFactors : ''
Categories : 'Qt - KDE - System'
---- Offer 4 ----
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
X-DBUS-ServiceName : 'org.kde.gwenview'
X-DocPath : 'gwenview/index.html'
Type : 'Application'
Name : 'Gwenview'
Comment : 'Ein einfacher Bildbetrachter'
GenericName : 'KDE-Bildbetrachter'
Icon : 'gwenview'
Exec : 'gwenview %U'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - image/gif - image/jpeg - image/png - image/bmp - image/x-eps - image/x-ico - image/x-portable-bitmap - image/x-portable-graymap - image/x-portable-pixmap - image/x-xbitmap - image/x-xpixmap - image/tiff - image/x-psd - image/x-webp - image/webp - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '8'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/org.kde.gwenview.desktop'
DesktopEntryName : 'org.kde.gwenview'
Keywords : ''
FormFactors : ''
Categories : 'Graphics - RasterGraphics - Viewer - KDE'
---- Offer 5 ----
X-DocPath : 'dolphin/index.html'
X-KDE-SubstituteUID : 'TRUE'
Type : 'Application'
Name : 'File Manager - Super User Mode'
Invalid property Comment
Invalid property GenericName
Icon : 'system-file-manager'
Exec : 'dbus-launch dolphin %i -qwindowtitle "%c" "%u"'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/org.kde.dolphinsu.desktop'
DesktopEntryName : 'org.kde.dolphinsu'
Keywords : ''
FormFactors : ''
Categories : 'Qt - KDE - System - FileManager'
---- Offer 6 ----
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
X-DocPath : 'cervisia/index.html'
Type : 'Application'
Name : 'Cervisia'
Invalid property Comment
GenericName : 'Grafische Oberfläche für CVS'
Icon : 'cervisia'
Exec : 'cervisia -caption %c %i %u'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/kde4/cervisia.desktop'
DesktopEntryName : 'cervisia'
Keywords : ''
FormFactors : ''
Categories : 'Qt - KDE - Development - RevisionControl'
---- Offer 7 ----
NoDisplay : 'TRUE'
StartupNotify : 'TRUE'
TryExec : 'Thunar'
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
Request for unknown property "X-SuSE-translate"
Invalid property X-SuSE-translate
Type : 'Application'
Name : 'Ordner in Thunar öffnen'
Comment : 'Angegebene Ordner mit Thunar öffnen'
GenericName : 'Ordner öffnen'
Icon : 'Thunar'
Exec : 'thunar %F'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/Thunar-folder-handler.desktop'
DesktopEntryName : 'thunar-folder-handler'
Keywords : ''
FormFactors : ''
Categories : 'System - Utility - Core - GTK - FileManager - System'
---- Offer 8 ----
StartupNotify : 'TRUE'
Request for unknown property "UntranslatedGenericName"
Invalid property UntranslatedGenericName
Request for unknown property "X-GNOME-Bugzilla-Bugzilla"
Invalid property X-GNOME-Bugzilla-Bugzilla
Request for unknown property "X-GNOME-Bugzilla-Component"
Invalid property X-GNOME-Bugzilla-Component
Request for unknown property "X-GNOME-Bugzilla-Product"
Invalid property X-GNOME-Bugzilla-Product
Request for unknown property "X-GNOME-Bugzilla-Version"
Invalid property X-GNOME-Bugzilla-Version
Request for unknown property "X-GNOME-DocPath"
Invalid property X-GNOME-DocPath
Request for unknown property "X-MultipleArgs"
Invalid property X-MultipleArgs
Request for unknown property "X-SuSE-translate"
Invalid property X-SuSE-translate
Type : 'Application'
Name : 'Anjuta'
Comment : 'Software in einer integrierten Umgebung entwickeln'
GenericName : 'Integrierte Entwicklungsumgebung'
Icon : 'anjuta'
Exec : 'anjuta %U'
Terminal : 'FALSE'
Invalid property TerminalOptions
Invalid property Path
ServiceTypes : 'application/x-anjuta - application/x-anjuta-project-template - application/x-anjuta-compressed-project-template - inode/directory - Application'
AllowAsDefault : 'TRUE'
InitialPreference : '1'
Invalid property Library
DesktopEntryPath : '/usr/share/applications/anjuta.desktop'
DesktopEntryName : 'anjuta'
Keywords : 'IDE - Entwicklung - Programmierung'
FormFactors : ''
Categories : 'GNOME - GTK - Development - IDE'



In a Terminal, the command "kde-open5" gives the following output:

Florian@linux-vaio:~> kde-open5
kde-open5: Syntaxfehler, zu wenig Argumente

If i click on a folder, Nautilus opens

The command was `kde-open5 .` , i.e. with a directory like "." as argument. But given the ktraderclient5 results, it will open Nautilus. OK so the problem is the reading of mimeapps.list when updating sycoca.

* is $XDG_CONFIG_HOME set? (I guess not, which is fine, just wanted to check)
* does it help if you run kbuildsycoca5, after mimeapps.list got modified, and before running ktraderclient5 or kde-open5 ?

kde-open5 . starts Nautilus, too. 
If i run kbuildsycoca5 manually, i get the following output:

Florian@linux-vaio:~> kbuildsycoca5
kbuildsycoca5 running...
Reusing existing ksycoca
Recreating ksycoca file ("/home/Florian/.cache/ksycoca5_de_eUqES8aVpgaKYzFUhUwmGK10wyE=", version 303)
Still in the time dict (i.e. deleted files) ("apps")
Menu "applications-kmenuedit.menu" not found.
Saving

Folder are still opened with nautilus after doing so...

What do you mean with this question?

* is $XDG_CONFIG_HOME set? (I guess not, which is fine, just wanted to check)

(In reply to David Faure from comment #4)
> OK, in my tests it works but I have a very different environment. Can you
> help me debug this remotely?
> 
> Please revert to the situation where it's broken, e.g. by deleting/renaming
> ~/.config/mimeapps.list  and ~/.local/share/applications/mimeapps.list. Make
> sure it's broken again, then let's debug ;)
> 
> When you select dolphin in the control center, what gets written into
> ~/.config/mimeapps.list ?
> What is the first offer in `ktraderclient5 --mimetype inode/directory` ?
>    [I just improved that tool so that next time the output is much shorter]
> What program opens if you run `kde-open5 .` in a terminal ?
> If that works, what action do you use, which results in the wrong
> filemanager opening?

I did the work around of re-ordering of the file manager options to put dolphin at the top and all worked fine.  I've now reverted the list to make gwenview at the top. When i now select Dolphin (second on the list) from the list and press apply, the change now sticks quite happily. SO i can no longer get it to go wrong on this user, i will try the other users to see if i can get it to go wrong.

I've now tried my other users but there's a problem.  If i go back into the inode bit and change the "Application Preference Order" list to put gwenview back on top, as soon as i press apply, it puts dolphin back on top of the list in the dialog so i can't change the order of appearance in order to test the "File Manager" change. This probably explains why it works in my previous comment as i didn;t check the order in the list when i changed it.

Another question about selecting "Other" in the File Manger default app association
It references a dialog where you is says "click Add in the dialogue show here" which assumes the dialogue box is already open but its not,  there is only a "button" on the far right with 3 dots on it which does display the dialogue when pressed - is this the correct way it should work?

The file manager change not sticking is a manifestation of the same bug. Discrepancy between saving and loading (new setting saved, old setting loaded). The two kcontrol modules have different saving code, but the loading code is the same.

Florian: the syntax $FOO refers to environment variable. To check if an env var is set, do
  echo $XDG_CONFIG_HOME
in a terminal (I expect this one to be empty)

Does `echo $XDG_CURRENT_DESKTOP` show "KDE" ?

Is there a ~/.config/kde-mimeapps.list maybe?

What do these commands return?
qtpaths --locate-files GenericConfigLocation kde-mimeapps.list
qtpaths --locate-files GenericConfigLocation mimeapps.list
qtpaths --locate-files ApplicationsLocation kde-mimeapps.list
qtpaths --locate-files ApplicationsLocation mimeapps.list

(In reply to Ian from comment #11)
> It references a dialog where you is says "click Add in the dialogue show
> here" which assumes the dialogue box is already open but its not,  there is
> only a "button" on the far right with 3 dots on it which does display the
> dialogue when pressed - is this the correct way it should work?

The point is:
1) click on the 3-dots button
2) a dialog appears
3) click "Add..." in *that* dialog, to select a new app
4) it will then appear in the initial kcontrol module

Somewhat suboptimal, but off topic for this bug :)

I can indeed reproduce the behaviours described here when a ~/.config/kde-mimeapps.list file exists, because it takes precedence over ~/.config/mimeapps.list even though that's where the GUI writes out changes. So changes don't stick. I'll think of a solution to fix that. But I'd still like to know if this is what you're hitting :-)

Hi David, 
there is no ~/.config/kde-mimeapps.list

The demanded commands return:

Florian@linux-vaio:~> echo $XDG_CONFIG_HOME

Florian@linux-vaio:~> echo $XDG_CURRENT_DESKTOP
KDE
Florian@linux-vaio:~> qtpaths --locate-files GenericConfigLocation kde-mimeapps.list

Florian@linux-vaio:~> qtpaths --locate-files GenericConfigLocation mimeapps.list    
/home/Florian/.config/mimeapps.list
Florian@linux-vaio:~> qtpaths --locate-files ApplicationsLocation kde-mimeapps.list
Unknown location: ApplicationsLocation
Florian@linux-vaio:~> qtpaths --locate-files ApplicationsLocation mimeapps.list    
Unknown location: ApplicationsLocation

I cant tell why, but now the setting works just fine. I did not change anything but typing in the commands you wanted...strange

Florian: My commands only query stuff, they didn't change anything ;)
(kbuildsycoca5 might have, but it's also what the GUI does, in theory)

Your qtpaths is too old to support ApplicationsLocation unfortunately so try this instead
qtpaths --locate-files GenericDataLocation applications/kde-mimeapps.list
qtpaths --locate-files GenericDataLocation applications/mimeapps.list

I know they did not change anything. Thats why this is so strange. 

Florian@linux-vaio:~> qtpaths --locate-files GenericDataLocation applications/kde-mimeapps.list

Florian@linux-vaio:~> qtpaths --locate-files GenericDataLocation applications/mimeapps.list
/home/Florian/.local/share/applications/mimeapps.list:/usr/share/applications/mimeapps.list
Florian@linux-vaio:~> 

I just saw that my system did an update about 2 hours ago. Maybe the OpenSUSE maintainers did something wrong, but now it works.

Argh, don't change other "variables" in the middle of debugging :-)

I wonder if the environment is different in GUI apps and in your terminal (starting `kcmshell5 componentchooser` from the same terminal would be a way to find out), but as long as you can't reproduce the bug anymore we can't do anything else.

It made me discover one bug (kde-mimeapps.list not cleaned up) and one possible improvement (ksycoca check on app startup should also check the timestamp of all mimeapps.list files), but from the above discussion, none of these were the actual problem, so I'm afraid there's still an underlying bug in kservice :(

Git commit 84e697f877e7cab2767b75448106b7e5abf27b10 by David Faure.
Committed on 28/02/2016 at 19:31.
Pushed by dfaure into branch 'master'.

keditfiletype: clean out any kde-mimeapps.list which would take precedence any cancel our changes.

M  +22   -3    keditfiletype/mimetypedata.cpp

http://commits.kde.org/kde-cli-tools/84e697f877e7cab2767b75448106b7e5abf27b10

Git commit 622a6d0a5a79c7919032c82e8e01127d8a4d1cdc by David Faure.
Committed on 28/02/2016 at 19:32.
Pushed by dfaure into branch 'master'.

componentchooser-filemanager: clean out any kde-mimeapps.list which would take precedence any cancel our changes.

M  +27   -5    kcms/componentchooser/componentchooserfilemanager.cpp

http://commits.kde.org/plasma-desktop/622a6d0a5a79c7919032c82e8e01127d8a4d1cdc

The mime files i found by :- find . -name "*mime*" in my home directory
./.kde4/share/config/mimeapps.list
./.local/share/applications/mimeapps.list
./.local/share/akonadi/db_data/akonadi/mimetypetable.ibd
./.local/share/akonadi/db_data/akonadi/collectionmimetyperelation.ibd
./.local/share/akonadi/db_data/akonadi/mimetypetable.frm
./.local/share/akonadi/db_data/akonadi/collectionmimetyperelation.frm
./.config/mimeapps.list
./.mozilla/firefox/22vtey90.default/mimeTypes.rdf

@David
sorry for my late response, i was quite busy the last days. I am really sorry for the change of "variables" :(
`kcmshell5 componentchooser` from the terminal simply opens the componentchooser window without any return from the terminal.

I do not have this bug in latest openSUSE Tumbleweed snapshot (20160305). Is the bug already fixed?

KDE-Plasma-Version: 5.5.4 (with some 5.5.5 packages)
Qt: 5.5.1

I think so, because i do not have it either. I just wanted to answer David's last question.

Amazing. So this really did look like a bad patch by the OpenSUSE packagers....

Closing the bug, since you guys can't reproduce the bug anymore.
Feel free to reopen it if it in fact still happens.

I think it is more linked to the way gnome (also xfce lxde) are now creating 
/var/cache/gio-2.0/[desktop]-mimeapps.list

for example the beginning of gnome is
# generated by suse-update-mime-defaults from /etc/gnome_defaults.conf
[Default Applications]
application/clarisworks=writer.desktop
application/csv=calc.desktop

in /etc/gnome_defaults.conf we have
# This list is a source for defaults.list.
#
# If application in this list is installed, it is used as default in GNOME.
# It works in following way:
# 1. Read this file.
# 2. Collect all available desktop files.
# 3. Go through all declared MIME types and search for default application
#    for defaults.list in following order:
# 3.1 Installed application listed here for certain MIME type.
# 3.2 Installed application listed here as preferred default.
# 3.3 Installed application listed here as default.
# 3.4 Installed application with GNOME in Categories.
# 3.5 Installed application with GTK in Categories.
# 3.6 Installed application.
# If there are more applications in the same order, it uses pseudo-randomly
# one of them (last in aplhabetical order).
#
# Syntax:
# Use xxx as default for all MIME types it declares (see 3.3):
# xxx.desktop
# Use xxx as preferred default for all MIME types it declares (see 3.2):
# !xxx.desktop
# Use xxx as default for mime/type (see 3.1):
# mime/type=xxx.desktop

# URI schemes
x-scheme-handler/http=firefox.desktop
x-scheme-handler/https=firefox.desktop
.....

I remember (but didn't yet find again) a discussion in the -factory ml reporting a misbehavior of kde
if certain files ( certainly *mime* related).