avoid dereferencing nil type on undefined name.
avoid dereferencing nil type on undefined name.

R=ken
DELTA=12  (12 added, 0 deleted, 0 changed)
OCL=15506
CL=15528

pombredanne/go-deleteme,pombredanne/go-deleteme,ssrl/go,wesolows/golang-old,bdwalton/debian-golang,tianon/debian-golang,nightlyone/golang,wesolows/golang,firebitsbr/golang-old,pombredanne/go-deleteme,gnanderson/go,tianon/debian-golang,apparentlymart/golang,bdwalton/debian-golang,firebitsbr/golang-old,h8liu/golang,wesolows/golang,gnanderson/go,wesolows/golang-old,pombredanne/go-deleteme,nightlyone/golang,dsriram/golang,h8liu/golang,tianon/debian-golang,apparentlymart/golang,ssrl/go,dsriram/golang,apparentlymart/golang,ssrl/go,bdwalton/debian-golang,bdwalton/debian-golang,wesolows/golang,ssrl/go,tv42/old-go,ssrl/go,wesolows/golang-old,nightlyone/golang,bdwalton/debian-golang,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,tianon/debian-golang,dsriram/golang,tianon/debian-golang,firebitsbr/golang-old,bdwalton/debian-golang,nightlyone/golang,tv42/old-go,bdwalton/debian-golang,gnanderson/go,gnanderson/go,dsriram/golang,wesolows/golang-old,gnanderson/go,h8liu/golang,bdwalton/debian-golang,tianon/debian-golang,wesolows/golang,ssrl/go,apparentlymart/golang,tianon/debian-golang,tv42/old-go,wesolows/golang-old,tv42/old-go,ssrl/go,tianon/debian-golang,gnanderson/go,dsriram/golang,tv42/old-go,wesolows/golang-old,apparentlymart/golang,nightlyone/golang,pombredanne/go-deleteme,firebitsbr/golang-old,gnanderson/go,h8liu/golang,apparentlymart/golang,h8liu/golang,h8liu/golang,wesolows/golang,apparentlymart/golang,firebitsbr/golang-old,h8liu/golang,dsriram/golang,firebitsbr/golang-old,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,firebitsbr/golang-old,tv42/old-go,nightlyone/golang,pombredanne/go-deleteme,wesolows/golang,nightlyone/golang