Fix regression bug: opening URLs didn't work

Fix #68 and #73

autoload/vimwiki/base.vim

@@ -510,7 +510,13 @@ function! vimwiki#base#open_link(cmd, link, ...) "{{{
   let [idx, scheme, path, subdir, lnk, ext, url, anchor] =
         \ vimwiki#base#resolve_scheme(a:link, 0)
 
-  if path == ''
+  " wikilinks of the form [[#anchor]]
+  if url == '' && anchor != ''
+    let lnk = expand('%:t:r')
+    let url = path.subdir.lnk.ext
+  endif
+
+  if url == ''
     if g:vimwiki_debug
       echom 'open_link: idx='.idx.', scheme='.scheme.', path='.path.', subdir='.subdir.', lnk='.lnk.', ext='.ext.', url='.url.', anchor='.anchor
     endif
@@ -518,11 +524,6 @@ function! vimwiki#base#open_link(cmd, link, ...) "{{{
     return
   endif
 
-  if url == ''
-    let lnk = expand('%:t:r')
-    let url = path.subdir.lnk.ext
-  endif
-
   let update_prev_link = ( (scheme == '' || scheme =~ 'wiki' || scheme =~ 'diary')
         \ && lnk != expand('%:t:r')
         \ ? 1 : 0)

doc/vimwiki.txt

@@ -2239,11 +2239,11 @@ similar to 'local:' and 'file:' schemes, but are always opened with Vim: >
            \ ', subdir='.subdir.', lnk='.lnk.', ext='.ext.', url='.url.
            \ ', anchor='.anchor
     endif
-    if path == ''
+    if url == '' && anchor == ''
       echom 'Vimwiki Error: Unable to resolve link!'
       return 0
     else
-      call vimwiki#base#edit_file('tabnew', url, '', [], 0)
+      call vimwiki#base#edit_file('tabnew', url, anchor, [], 0)
       return 1
     endif
   endfunction " }}}