Fix field splitting on outside spaces

* geesh/word.scm (split-fields): Make outside spaces in word-parts
count for field splitting.
* tests/word.scm: Test this.

geesh/word.scm

@@ -75,12 +75,13 @@ set @var{ifs}."
       (str (let ((str-parts (string-split str ifs)))
              (if (every string-null? str-parts)
                  '(wedge)
-                 (infix 'wedge (filter (compose not string-null?)
-                                       str-parts)))))))
+                 (filter (lambda (x)
+                           (or (eq? x 'wedge) (not (string-null? x))))
+                         (infix 'wedge str-parts)))))))
 
   (let ((wedged (append-map (cut wedge-apart <> ifs)
                             (normalize-word qword))))
-    (list-split wedged 'wedge)))
+    (filter pair? (list-split wedged 'wedge))))
 
 (define (remove-quotes qword)
   "Remove quote forms from @var{qword} and concatenate the result into a

tests/word.scm

@@ -60,6 +60,14 @@ the `set' built-in for details on these options.)"
   '("foo" "bar")
   (expand-word #f '("foo bar")))
 
+(test-equal "Splits a word on leading space"
+  '("foo" "bar")
+  (expand-word #f '("foo" " bar")))
+
+(test-equal "Splits a word on trailing space"
+  '("foo" "bar")
+  (expand-word #f '("foo " "bar")))
+
 (test-equal "Ignores leading spaces"
   '("foo")
   (expand-word #f '(" foo")))