segfault when opening an IMAP directory

[c-cube]

open mutt-kz, go to a directory (using either the sidebar or c), witness error. I joined the valgrind log.

Version (obtained from AUR with the additional flag --enable-sidebar):

Mutt 1.6.0.1 (2016-04-01)
Copyright (C) 1996-2016 Michael R. Elkins and others.
Mutt comes with ABSOLUTELY NO WARRANTY; for details type `mutt -vv'.
Mutt is free software, and you are welcome to redistribute it
under certain conditions; type `mutt -vv' for details.

System: Linux 4.6.4-1-ARCH (x86_64)
ncurses: ncurses 6.0.20150808 (compiled with 6.0)
libidn: 1.33 (compiled with 1.33)
hcache backend: GDBM version 1.12. 16/05/2016 (built May 31 2016 18:36:34)

Compiler:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --disable-multilib --disable-werror --enable-checking=release
Thread model: posix
gcc version 6.1.1 20160802 (GCC) 

Configure options: '--enable-notmuch' '--prefix=/usr' '--sysconfdir=/etc' '--enable-gpgme' '--enable-pop' '--enable-imap' '--enable-smtp' '--enable-pgp' '--enable-hcache' '--enable-sidebar' '--with-curses=/usr' '--with-regex' '--with-gss=/usr' '--with-ssl=/usr' '--with-sasl' '--with-idn' 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong' 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro' 'CPPFLAGS=-D_FORTIFY_SOURCE=2'

Compilation CFLAGS: -Wall -pedantic -Wno-long-long -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong

Compile options:
-DOMAIN
-DEBUG
-HOMESPOOL  -USE_SETGID  +USE_DOTLOCK  -DL_STANDALONE  +USE_FCNTL  -USE_FLOCK   
+USE_POP  +USE_IMAP  +USE_SMTP  
+USE_SSL_OPENSSL  -USE_SSL_GNUTLS  +USE_SASL  +USE_GSS  +HAVE_GETADDRINFO  
-HAVE_REGCOMP  +USE_GNU_REGEX  
+HAVE_COLOR  +HAVE_START_COLOR  +HAVE_TYPEAHEAD  +HAVE_BKGDSET  
+HAVE_CURS_SET  +HAVE_META  +HAVE_RESIZETERM  
+CRYPT_BACKEND_CLASSIC_PGP  +CRYPT_BACKEND_CLASSIC_SMIME  +CRYPT_BACKEND_GPGME  
-EXACT_ADDRESS  -SUN_ATTACHMENT  
+ENABLE_NLS  -LOCALES_HACK  +HAVE_WC_FUNCS  +HAVE_LANGINFO_CODESET  +HAVE_LANGINFO_YESEXPR  
+HAVE_ICONV  -ICONV_NONTRANS  +HAVE_LIBIDN  +HAVE_GETSID  +USE_HCACHE  +USE_SIDEBAR  +NOTMUCH     
-ISPELL
SENDMAIL="/usr/sbin/sendmail"
MAILPATH="/var/mail"
PKGDATADIR="/usr/share/mutt-kz"
SYSCONFDIR="/etc"
EXECSHELL="/bin/sh"
-MIXMASTER
To contact the developers, please mail to <mutt-dev@mutt.org>.
To report a bug, please visit http://bugs.mutt.org/.

patch-quasi-delete-neo-UNKNOWN
patch-progress-neo-UNKNOWN
patch-status-color-neo-UNKNOWN
patch-index-color-neo-UNKNOWN
patch-nested-if-neo-UNKNOWN
patch-cond-date-neo-UNKNOWN
patch-tls-sni-neo-UNKNOWN
patch-sidebar-neo-UNKNOWN