Why does the gluster/nfs process crash on V3 UMNTALL from a Windows client?

Issue

• gluster/nfs process crashes with the below trace, when mnt3svc_umountall issued from a Windows client

[2017-01-31 09:36:12.603199] E [mem-pool.c:305:__gf_free] (-->/usr/lib64/glusterfs/3.7.1/xlator/nfs/server.so(__mnt3svc_umountall+0x65) [0x7f2c8aa6ca05] -->/lib64/libglusterfs.so.0(dict_del+
 0xcf) [0x7f2c98df636f] -->/lib64/libglusterfs.so.0(__gf_free+0x9c) [0x7f2c98e3131c] ) 0-: Assertion failed: GF_MEM_HEADER_MAGIC == header->magic
pending frames:
frame : type(0) op(0)
frame : type(0) op(0)
patchset: git://git.gluster.com/glusterfs.git
signal received: 6
time of crash: 
2017-01-31 09:36:12
configuration details:
argp 1
backtrace 1
dlfcn 1
libpthread 1
llistxattr 1
setfsid 1
spinlock 1
epoll.h 1
xattr.h 1
st_atim.tv_nsec 1
package-string: glusterfs 3.7.1
/lib64/libglusterfs.so.0(_gf_msg_backtrace_nomem+0xb2)[0x7f2c98dfde92]
/lib64/libglusterfs.so.0(gf_print_trace+0x32d)[0x7f2c98e1a4ed]
/lib64/libc.so.6(+0x35670)[0x7f2c974ea670]
/lib64/libc.so.6(gsignal+0x37)[0x7f2c974ea5f7]
/lib64/libc.so.6(abort+0x148)[0x7f2c974ebce8]
/lib64/libc.so.6(+0x75327)[0x7f2c9752a327]
/lib64/libc.so.6(+0x7d053)[0x7f2c97532053]
/lib64/libglusterfs.so.0(dict_del+0xcf)[0x7f2c98df636f]
/usr/lib64/glusterfs/3.7.1/xlator/nfs/server.so(__mnt3svc_umountall+0x65)[0x7f2c8aa6ca05]
/usr/lib64/glusterfs/3.7.1/xlator/nfs/server.so(mnt3svc_umountall+0x22)[0x7f2c8aa6ca72]
/usr/lib64/glusterfs/3.7.1/xlator/nfs/server.so(mnt3svc_umntall+0x3b)[0x7f2c8aa6cacb]
/lib64/libglusterfs.so.0(synctask_wrap+0x12)[0x7f2c98e40102]
/lib64/libc.so.6(+0x47110)[0x7f2c974fc110]