Bug#1145644: libkpim6messagecomposer6: kmail exits when closing message composer window

Package: libkpim6messagecomposer6
Version: 4:26.04.3-7
Severity: important

Dear Maintainer,

After upgrading my system to versions 4:26.04.3-7 of the messagelib
libraries, KMail/Kontact exits when ever I close the message composer.
First I observed this when sending a message, but it actually happens
even after
  - start kmail
  - click "New Message"
  - close the new message window
kmail then closes completely, but no crash handler is opened

when starting kmail from the commandline the last output lines are

```
free(): invalid next size (normal)
*** KMail got signal 6 (Exiting)
*** Dead letters dumped.
Alarm clock                kmail
```

Based on this observations I downgraded all the binaries from
messagelib to 4:26.04.3-2. And this fixed the problem.

(so I can not guarantee that the affected binary package is really
messagecomposer6 but this is the most likely culprit.)

Thanks for your work!

Nicola


-- System Information:
Debian Release: forky/sid
  APT prefers stable-security
  APT policy: (990, 'stable-security'), (900, 'testing'), (500, 'testing-debug'), (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 7.1.8+deb14.1-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages libkpim6messagecomposer6 depends on:
ii  kio6                                                         6.28.0-1
ii  libc6                                                        2.43-3
ii  libgcc-s1                                                    16.2.0-1
ii  libgpgmepp7                                                  2.1.0-2
ii  libkf6calendarcore6                                          6.28.0-1
ii  libkf6codecs6                                                6.28.0-1
ii  libkf6completion6                                            6.28.0-1
ii  libkf6configcore6                                            6.28.0-1
ii  libkf6configgui6                                             6.28.0-1
ii  libkf6contacts6                                              6.28.0-2
ii  libkf6coreaddons6                                            6.28.0-2
ii  libkf6guiaddons6                                             6.28.0-1
ii  libkf6i18n6                                                  6.28.0-1
ii  libkf6jobwidgets6                                            6.28.0-1
ii  libkf6kiocore6                                               6.28.0-1
ii  libkf6kiogui6                                                6.28.0-1
ii  libkf6kiowidgets6                                            6.28.0-1
ii  libkf6service-bin                                            6.28.0-1
ii  libkf6service6                                               6.28.0-1
ii  libkf6sonnetui6                                              6.28.0-1
ii  libkf6textaddonswidgets1                                     2.0.2-3
ii  libkf6textautocorrectioncore1                                2.0.2-3
ii  libkf6textcustomeditor1                                      2.0.2-3
ii  libkf6widgetsaddons6                                         6.28.0-1
ii  libkf6xmlgui6                                                6.28.0-1
ii  libkpim6akonadicontactcore6 [libkpim6akonadicontactcore6-26  4:26.04.3-2
    .04]
ii  libkpim6akonadicontactwidgets6 [libkpim6akonadicontactwidge  4:26.04.3-2
    ts6-26.04]
ii  libkpim6akonadicore6 [libkpim6akonadicore6-26.04]            4:26.04.3-2
ii  libkpim6akonadimime6 [libkpim6akonadimime6-26.04]            4:26.04.3-2
ii  libkpim6akonadiwidgets6 [libkpim6akonadiwidgets6-26.04]      4:26.04.3-2
ii  libkpim6identitymanagementcore6 [libkpim6identitymanagement  26.04.3-2
    core6-26.04]
ii  libkpim6identitymanagementwidgets6 [libkpim6identitymanagem  26.04.3-2
    entwidgets6-26.04]
ii  libkpim6libkdepim6 [libkpim6libkdepim6-26.04]                4:26.04.3-2
ii  libkpim6libkleo6 [libkpim6libkleo6-26.04]                    4:26.04.3-2
ii  libkpim6mailtransport6 [libkpim6mailtransport6-26.04]        26.04.3-2
hi  libkpim6messagecore6 [libkpim6messagecore6-26.04]            4:26.04.3-2
hi  libkpim6messageviewer6 [libkpim6messageviewer6-26.04]        4:26.04.3-2
ii  libkpim6mime6 [libkpim6mime6-26.04]                          26.04.3-2
hi  libkpim6mimetreeparser6 [libkpim6mimetreeparser6-26.04]      4:26.04.3-2
ii  libkpim6pimcommon6 [libkpim6pimcommon6-26.04]                4:26.04.3-2
ii  libkpim6pimcommonakonadi6 [libkpim6pimcommonakonadi6-26.04]  4:26.04.3-2
hi  libkpim6templateparser6 [libkpim6templateparser6-26.04]      4:26.04.3-2
ii  libkpim6textedit6 [libkpim6textedit6-26.04]                  26.04.3-2
ii  libqgpgmeqt6-15                                              2.2.0-2
ii  libqt6core6t64                                               6.10.2+dfsg-16
ii  libqt6dbus6                                                  6.10.2+dfsg-16
ii  libqt6gui6                                                   6.10.2+dfsg-16
ii  libqt6widgets6                                               6.10.2+dfsg-16
ii  libstdc++6                                                   16.2.0-1
hi  messagelib-data                                              4:26.04.3-2

libkpim6messagecomposer6 recommends no packages.

libkpim6messagecomposer6 suggests no packages.

-- no debconf information