[xubuntu] msdl installation - 2 errors making

yosi@yosi-VirtualBox:~/Downloads/msdl-1.2.7-r2$ make
make all-recursive
make[1]: Entering directory '/home/yosi/Downloads/msdl-1.2.7-r2'
Making all in src
make[2]: Entering directory '/home/yosi/Downloads/msdl-1.2.7-r2/src'
gcc -g -O2 -o msdl asf.o asmrule.o display.o ftp.o http.o main.o mmsh.o mmst.o msdl.o msdllib.o network.o progress.o real.o realchallenge.o rmff.o rtsp.o sdpcommon.o sdpreal.o sdpwms.o wmserver.o url.o
http.o: In function `http_encode_uri':
/home/yosi/Downloads/msdl-1.2.7-r2/src/http.c:456: undefined reference to `is_url_valid_char'
/home/yosi/Downloads/msdl-1.2.7-r2/src/http.c:467: undefined reference to `is_url_valid_char'
msdl.o: In function `get_url_list_from_file':
/home/yosi/Downloads/msdl-1.2.7-r2/src/msdl.c:361: undefined reference to `is_url_valid_char'
collect2: error: ld retued 1 exit status
Makefile:218: recipe for target 'msdl' failed
make[2]: *** [msdl] Error 1
make[2]: Leaving directory '/home/yosi/Downloads/msdl-1.2.7-r2/src'
Makefile:223: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/yosi/Downloads/msdl-1.2.7-r2'
Makefile:162: recipe for target 'all' failed
make: *** [all] Error 2