fix(rcs): avoid unexpected pathname expansion

In the current implementation, when the current word contains any glob
characters, the glob pattern can match unexpected files.  We instead
use `_comp_expand_glob` with double-quoting the strings originating
from the current word.

Author: akinomyoga

completions/rcs

@@ -21,7 +21,9 @@ _comp_cmd_rcs()
         COMPREPLY[i]=$dir$file
     done
 
-    _comp_compgen -aR -- -G "$dir/$file*,v"
+    local files
+    _comp_expand_glob files '"$dir/$file"*,v' &&
+        _comp_compgen -aR -- -W '"${files[@]}"'
 
     local i
     for i in ${!COMPREPLY[*]}; do