thunderbird-android: K9mail stuck in crash loop after a few days of usage

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App version

6.000

Where did you get the app from?

F-Droid

Android version

Android 7.1.1

Device model

Moto E4 plus

Steps to reproduce

On a phone in my family (but not my own phone), after using K9mail for a few days, K9mail crashes and then is stuck in a crash loop: each time K9mail is started, it immediately crashes again. The only way to recover is to uninstall K9mail and then reinstall and reconfigure everything. This has happened twice now.

The crash usually occurs when opening an email, but opening the same email again after reinstallation does not reproduce the problem. I don’t know how to trigger this problem, unfortunately. This started towards the end of April, shortly after 6.000 got released on F-droid.

Expected behavior

K9mail should not crash, and when it does, it should recover after restarting the application (or at least, restarting the phone).

Actual behavior

K9mail crashes and keeps crashing each time it is started.

Logs

Here’s what adb logcat says when I start K9mail: https://pastebin.com/4fpi2L4t

The crash seems to be this part:

05-15 16:24:30.851 23328 23328 F libc    : Fatal signal 11 (SIGSEGV), code 1, fault addr 0x19 in tid 23328 (com.fsck.k9)
05-15 16:24:30.853   690   690 D AEE_AED : $===AEE===AEE===AEE===$
05-15 16:24:30.853   690   690 D AEE_AED : p 2 poll events 1 revents 1
05-15 16:24:30.853   690   690 D AEE_AED : PPM cpu cores:4, online:4
05-15 16:24:30.854 23328 23359 W libEGL  : [ANDROID_RECORDABLE] format: 1
05-15 16:24:30.855   690   690 D AEE_AED : aed_main_fork_worker: generator 0xb0615170, worker 0xbeda68c4, recv_fd 0
05-15 16:24:30.856 23370 23370 I AEE_AED : handle_request(0)
05-15 16:24:30.856 23370 23370 I AEE_AED : check process 23328 name:com.fsck.k9
05-15 16:24:30.856 23370 23370 I AEE_AED : tid 23328 abort msg address:0x00000000, si_code:1 (request from 23328:10161)
05-15 16:24:30.856 23370 23370 W AEE_AED : debuggerd: handling request: pid=23328 uid=10161 gid=10161 tid=23328
05-15 16:24:30.858 23370 23370 I AEE_AED : [preset_info] pid: 23328, tid: 23328, name: com.fsck.k9  >>> com.fsck.k9 <<<
05-15 16:24:30.858 23370 23370 D AEE_AED : ptrace_siblings
05-15 16:24:30.859 23328 23359 D mali_winsys: EGLint new_window_surface(egl_winsys_display*, void*, EGLSurface, EGLConfig, egl_winsys_surface**, egl_color_buffer_format*, EGLBoolean) returns 0x3000
05-15 16:24:30.880 23370 23370 D AEE_AED : debuggerd: drop privileges
05-15 16:24:30.931 23370 23370 I AEE_AED : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
05-15 16:24:30.931 23370 23370 I AEE_AED : Build fingerprint: 'motorola/nicklaus_fn/nicklaus_fn:7.1.1/NMA26.42-162-1/1:user/release-keys'
05-15 16:24:30.931 23370 23370 I AEE_AED : Revision: 'MP'
05-15 16:24:30.931 23370 23370 I AEE_AED : ABI: 'arm'
05-15 16:24:30.931 23370 23370 I AEE_AED : pid: 23328, tid: 23328, name: UNKNOWN  >>> UNKNOWN <<<
05-15 16:24:30.931 23370 23370 I AEE_AED : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x19
05-15 16:24:30.932 23370 23370 I AEE_AED :     r0 00001e7f  r1 00000001  r2 00000000  r3 138fc710
05-15 16:24:30.932 23370 23370 I AEE_AED :     r4 794f9db8  r5 00000001  r6 13908790  r7 138d2c80
05-15 16:24:30.932 23370 23370 I AEE_AED :     r8 00000000  r9 af485400  sl 00000002  fp 138fc710
05-15 16:24:30.932 23370 23370 I AEE_AED :     ip 138fc000  sp beb8f7c0  lr 94bd4007  pc af03b3d0  cpsr 000d0030
05-15 16:24:30.934 23370 23370 I AEE_AED :
05-15 16:24:30.934 23370 23370 I AEE_AED : backtrace:
05-15 16:24:30.934 23370 23370 I AEE_AED :     #00 pc 000ae3d0  /system/lib/libart.so
05-15 16:24:30.934 23370 23370 I AEE_AED :     #01 pc 00c91005  /data/app/com.fsck.k9-1/oat/arm/base.odex (offset 0x97a000)