ENH: improve wmake handling of directory when given a source file

wmake/wmake

@@ -268,6 +268,10 @@ then
         then
             dir="${1%/*}"
             : "${dir:=.}"
+            if [ "$dir" = "$1" ]
+            then
+                dir="."
+            fi
         else
             echo "$Script error: not a file or directory" 1>&2
             exit 1
@@ -299,6 +303,10 @@ else
         then
             dir="${1%/*}"
             : "${dir:=.}"
+            if [ "$dir" = "$1" ]
+            then
+                dir="."
+            fi
         else
             targetType="$1"
         fi