update pandoc filters

pandoc/filters/collect_internal_linked.lua

@@ -8,18 +8,19 @@ local visited = {}
 
 return {
   { Link = function(link)
-    -- early return for visited
-    if visited[link.target] then return end
-    visited[link.target] = true
-
     -- early return for external links
     if link.target:find("^https?%:%/%/") then return end
     if link.target:find("^mailto%:") then return end
 
     local fp, anchor = link.target:match("^(.+%.md)#?(.*)$")
+
     -- early return for non markdown files
     if not fp then return end
 
+    -- early return for visited
+    if visited[fp] then return end
+    visited[fp] = true
+
     local f = io.open(fp)
     -- early return for broken internal links
     if f == nil then return link.content else f:close() end -- @todo maybe log broken internal links