Multiline argument with a character preceded by the escape character causes linting range to be off

[rcjsuen]

FROM alpine
COPY a b /di\
\
\r

$ docker build .
Sending build context to Docker daemon  38.15MB
Step 1/2 : FROM alpine
 ---> a187dde48cd2
Step 2/2 : COPY a b /di\r
When using COPY with more than one source file, the destination must be a directory and end with a /

$ docker run -v `pwd`/Dockerfile:/Dockerfile rcjsuen/dockerfile-utils lint /Dockerfile
Line: 2-3
COPY a b /di\
         ^^^^
\

Error: When using COPY with more than one source file, the destination must be a directory and end with a / or a \