opensuse 42.1 leap, open during start-up to full-screen. 
Take the program at the bar, tear it down (a re-size should happen). 
Instead it crashes silently with a segfault. No konqi comes up. 

Reproducible: Always

Steps to Reproduce:
1. opens kontact 5.1.2 in Leap full-screen
2. take it at the bar and tear it down to resize
3. crashes with segfault. 

Actual Results:  
Program segfaults if tearing on bar. Does not segfault if minimizing or closing to tray. 

Expected Results:  
Program should re-size from full-screen and not crash. 

The version of kontact/kmail 5.1.2 does not come as first choice, 4.12 (or 13?) is given. But the use of it is encouraged. 
The program segfaults silently but I will join the output when running on console. 
Note: this is independent if running it with imap support, or with pop. No matter, it crashes. 
It is also independent of the use of filters, of clamav etc. 
Graphics driver of this system is the intel i915. 
For the rest this system is practically standard with only packman joined. The 4.x version is not hit. 
Output of the CLI (the xxx are anonymizations). 

mercurio@linux-cujp:~> kontact
"KMail Kernel ETM"
()
""
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_JofKJF"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_Mbf8sk"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_dJUVRm"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_qBCFqQ"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_3OkzPI"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_0i4e0O"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_tMzWVs"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_E6Bgaa"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
"/subscriber/kontact_3580_TQmdga"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
done
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
org.kde.akonadi.ETM: GEN true false false
org.kde.akonadi.ETM: collection: QVector()
org.kde.akonadi.ETM: 
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
org.kde.akonadi.ETM: GEN true false true
org.kde.akonadi.ETM: collection: QVector()
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
org.kde.akonadi.ETM: GEN true false true
org.kde.akonadi.ETM: collection: QVector()
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
org.kde.akonadi.ETM: GEN true false true
org.kde.akonadi.ETM: collection: QVector()
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Read defaultResourceId "akonadi_maildir_resource_0" from config.
Found resource "akonadi_maildir_resource_0"
org.kde.akonadi.ETM: Subtree:  4 QSet(42, 43, 52, 53, 54, 55, 48, 49, 50, 51, 61, 63, 56, 57, 58, 69, 70, 4, 64, 5, 65, 6, 66, 7, 67, 76, 77, 78, 79, 72, 73, 9, 10, 11, 80, 81, 23, 82, 28, 29, 31, 25, 26, 27, 36, 38, 39, 32, 35, 45, 46, 47, 40)
org.kde.akonadi.ETM: collection: "Bugs-novell"
org.kde.akonadi.ETM: Subtree:  1 QSet(68, 1)
org.kde.akonadi.ETM: Fetch job took  320 msec
org.kde.akonadi.ETM: was collection fetch job: collections: 55
org.kde.akonadi.ETM: first fetched collection: "Search"
org.kde.akonadi.ETM: collection: "xxxxx"
org.kde.akonadi.ETM: collection: "xxxxx"
org.kde.akonadi.ETM: collection: "Deutsche Bahn Online tickets (last 8 weeks)"
org.kde.akonadi.ETM: collection: "Angelina"
org.kde.akonadi.ETM: collection: "xxxxx Asia aktivities"
Fetched 53 collections.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "highxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "mailbox.org" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "xxxxx Web.de Mail" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Deutsche Bahn Online tickets (last 8 weeks)" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Ct krypto" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "xxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "xxxxx.econ" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "signed PGP" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "belgacom account" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Frank xxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Stephanie xxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Vendita internet" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "stakanov" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "bicycle related" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Professional" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Elena xxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "xxxxx freenet" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "xxxxx" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "Whitelisted" -- not recovering.
Searching for names:  ("outbox", "drafts", "inbox", "sent-mail", "templates", "Cartelle locali", "trash")
Unknown collection name "ArchChinese" -- not recovering.
org.kde.akonadi.ETM: Fetch job took  375 msec
org.kde.akonadi.ETM: was collection fetch job: collections: 7
org.kde.akonadi.ETM: first fetched collection: "Search"
Fetched root collection 4 and 7 local folders (total 53 collections).
resourceId "akonadi_maildir_resource_0"
All done! Comitting.
Emitting changed for "akonadi_maildir_resource_0"
Emitting defaultFoldersChanged.
 PLUGIN : identifier "application/octet-stream@QByteArray"
registering Desktop file "/usr/share/akonadi/plugins/serializer//akonadi_serializer_addressee.desktop" for ("text/vcard", "text/directory") @ ("legacy", "default", "KContacts::Addressee")
registering Desktop file "/usr/share/akonadi/plugins/serializer//akonadi_serializer_contactgroup.desktop" for ("application/x-vnd.kde.contactgroup") @ ("legacy", "default", "KContacts::ContactGroup")
registering Desktop file "/usr/share/akonadi/plugins/serializer//akonadi_serializer_kalarm.desktop" for ("application/x-vnd.kde.alarm", "application/x-vnd.kde.alarm.active", "application/x-vnd.kde.alarm.archived", "application/x-vnd.kde.alarm.template") @ ("default", "KAlarmCal::KAEvent")
registering Desktop file "/usr/share/akonadi/plugins/serializer//akonadi_serializer_kcalcore.desktop" for ("text/calendar", "application/x-vnd.akonadi.note", "application/x-vnd.kde.notes") @ ("default", "KCalCore::Incidence*")
registering Desktop file "/usr/share/akonadi/plugins/serializer//akonadi_serializer_mail.desktop" for ("message/rfc822", "message/news", "text/x-vnd.akonadi.note") @ ("legacy", "default", "KMime::Message*")
ItemSerializerPluginLoader:  found 32 plugins. 

 PLUGIN : identifier "application/x-vnd.kde.alarm.archived@default"
 PLUGIN : identifier "application/x-vnd.akonadi.note@default"
 PLUGIN : identifier "message/news@legacy"
 PLUGIN : identifier "message/news@default"
 PLUGIN : identifier "application/x-vnd.kde.alarm.template@default"
 PLUGIN : identifier "application/x-vnd.kde.alarm.archived@KAlarmCal::KAEvent"
 PLUGIN : identifier "application/x-vnd.kde.alarm@KAlarmCal::KAEvent"
 PLUGIN : identifier "text/calendar@default"
 PLUGIN : identifier "application/x-vnd.kde.notes@default"
 PLUGIN : identifier "application/x-vnd.kde.contactgroup@default"
 PLUGIN : identifier "text/x-vnd.akonadi.note@legacy"
 PLUGIN : identifier "text/x-vnd.akonadi.note@KMime::Message*"
 PLUGIN : identifier "application/x-vnd.kde.notes@KCalCore::Incidence*"
 PLUGIN : identifier "text/directory@default"
 PLUGIN : identifier "message/rfc822@default"
 PLUGIN : identifier "application/x-vnd.kde.contactgroup@KContacts::ContactGroup"
 PLUGIN : identifier "application/x-vnd.kde.contactgroup@legacy"
 PLUGIN : identifier "application/x-vnd.akonadi.note@KCalCore::Incidence*"
 PLUGIN : identifier "message/rfc822@KMime::Message*"
 PLUGIN : identifier "text/directory@KContacts::Addressee"
 PLUGIN : identifier "text/vcard@legacy"
 PLUGIN : identifier "text/vcard@KContacts::Addressee"
 PLUGIN : identifier "message/rfc822@legacy"
 PLUGIN : identifier "application/x-vnd.kde.alarm.active@default"
 PLUGIN : identifier "text/calendar@KCalCore::Incidence*"
 PLUGIN : identifier "text/vcard@default"
 PLUGIN : identifier "text/x-vnd.akonadi.note@default"
 PLUGIN : identifier "application/x-vnd.kde.alarm@default"
 PLUGIN : identifier "application/x-vnd.kde.alarm.template@KAlarmCal::KAEvent"
 PLUGIN : identifier "text/directory@legacy"
 PLUGIN : identifier "message/news@KMime::Message*"
 PLUGIN : identifier "application/x-vnd.kde.alarm.active@KAlarmCal::KAEvent"
org.kde.akonadi.ETM: Fetch job took  197 msec
org.kde.akonadi.ETM: was item fetch job: items: 199
"/subscriber/kontact_3580_JBCpvg"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
org.kde.akonadi.ETM: Fetch job took  180 msec
org.kde.akonadi.ETM: was item fetch job: items: 359
org.kde.akonadi.ETM: Fetch job took  252 msec
org.kde.akonadi.ETM: was item fetch job: items: 49
org.kde.akonadi.ETM: Fetch job took  270 msec
org.kde.akonadi.ETM: was item fetch job: items: 23
org.kde.akonadi.ETM: Fetch job took  284 msec
org.kde.akonadi.ETM: was item fetch job: items: 59
org.kde.akonadi.ETM: Subtree:  2 QSet(2)
org.kde.akonadi.ETM: Subtree:  12 QSet(12)
org.kde.akonadi.ETM: Subtree:  1 QSet(84, 83, 1)
org.kde.akonadi.ETM: Fetch job took  581 msec
org.kde.akonadi.ETM: was collection fetch job: collections: 5
org.kde.akonadi.ETM: first fetched collection: "Search"
org.kde.akonadi.ETM: Fetch job took  299 msec
org.kde.akonadi.ETM: was item fetch job: items: 10
org.kde.akonadi.ETM: Subtree:  12 QSet(12)
org.kde.akonadi.ETM: Subtree:  1 QSet(84, 83, 1)
org.kde.akonadi.ETM: Fetch job took  592 msec
org.kde.akonadi.ETM: was collection fetch job: collections: 4
org.kde.akonadi.ETM: first fetched collection: "Search"
org.kde.akonadi.ETM: Subtree:  14 QSet(14)
org.kde.akonadi.ETM: Fetch job took  595 msec
org.kde.akonadi.ETM: was collection fetch job: collections: 1
org.kde.akonadi.ETM: first fetched collection: "Note"
"kontact-1186278907-SearchSession"
connectToServer "/tmp/akonadi-mercurio.fvXuTF/akonadiserver.socket"
Connected to "Akonadi" , using protocol version 52
Server says: "Not Really IMAP server"
Errore di segmentazione