fix pagetree->path (closes #249)

Pagetree promises that its nodes will be resolved relative to the directory where the pagetree lives. For path-based pagetrees, make sure this directory is set correctly.

pollen/pagetree.rkt

@@ -220,11 +220,12 @@
 
 (define+provide/contract (pagetree->paths pt-or-path)
   ((or/c pagetree? pathish?) . -> . (listof complete-path?))
-  (parameterize ([current-directory (current-project-root)])
-    (map ->complete-path (pagetree->list (match pt-or-path
-                                           [(? pagetree? pt) pt]
-                                           [_ (cached-doc pt-or-path)])))))
-
+  (define-values (dir-for-resolving-paths pt)
+    (match pt-or-path
+      [(? pagetree?) (values (current-project-root) pt-or-path)]
+      [_ (values (dirname (->path pt-or-path)) (cached-doc pt-or-path))]))
+  (parameterize ([current-directory dir-for-resolving-paths])
+    (map ->complete-path (pagetree->list pt))))
 
 (module-test-external
  (define test-pagetree `(pagetree-main foo bar (one (two three))))

pollen/private/ts.rktd

@@ -1 +1 @@
-1614969950
+1615271301