sipe-media.c:1904:14: error: this statement may fall through [-Werror=implicit-fallthrough=]

I'm getting a compile error on the launchpad branch:

libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../.. -Werror -Wall -Wextra -Waggregate-return -Wcast-align -Wdeclaration-after-statement -Wdeprecated-declarations -Winit-self -Wmaybe-uninitialized -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wundef -Wunused-but-set-variable -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -pthread -I/usr/include/gio-unix-2.0/ -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -pthread -DLOCALEDIR=\"/usr/share/locale\" -I./../api -I/usr/include/freerdp2/ -I/usr/include/winpr2 -I/usr/include/nss3 -I/usr/include/nspr4 -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic -c sipe-digest-nss.c  -fPIC -DPIC -o .libs/libsipe_core_crypto_la-sipe-digest-nss.o
sipe-media.c: In function ‘process_invite_call_response’:
sipe-media.c:1904:14: error: this statement may fall through [-Werror=implicit-fallthrough=]
    case 488: {
              ^
sipe-media.c:1937:4: note: here
    default:
    ^~~~~~~
cc1: all warnings being treated as errors
make[3]: *** [Makefile:1505: libsipe_core_la-sipe-media.lo] Error 1

Wondering what the intention is here.

tieto / sipe

sipe-media.c:1904:14: error: this statement may fall through [-Werror=implicit-fallthrough=] #160