1 files changed, 43 insertions, 21 deletions

diff --git a/src/url.lua b/src/url.lua
index 110ea94..0a3a80a 100644
--- a/src/url.lua
+++ b/src/url.lua
@@ -77,6 +77,34 @@ function _M.unescape(s)
 end
 
 -----------------------------------------------------------------------------
+-- Removes '..' and '.' components appropriately from a path.
+-- Input
+--   path
+-- Returns
+--   dot-normalized path
+local function remove_dot_components(path)
+    local marker = string.char(1)
+    repeat
+        local was = path
+        path = path:gsub('//', '/'..marker..'/', 1)
+    until path == was
+    repeat
+        local was = path
+        path = path:gsub('/%./', '/', 1)
+    until path == was
+    repeat
+        local was = path
+        path = path:gsub('[^/]+/%.%./([^/]+)', '%1', 1)
+    until path == was
+    path = path:gsub('[^/]+/%.%./*$', '')
+    path = path:gsub('/%.%.$', '/')
+    path = path:gsub('/%.$', '/')
+    path = path:gsub('^/%.%./', '/')
+    path = path:gsub(marker, '')
+    return path
+end
+
+-----------------------------------------------------------------------------
 -- Builds a path from a base path and a relative path
 -- Input
 --   base_path
@@ -85,23 +113,12 @@ end
 --   corresponding absolute path
 -----------------------------------------------------------------------------
 local function absolute_path(base_path, relative_path)
-    if string.sub(relative_path, 1, 1) == "/" then return relative_path end
-    local path = string.gsub(base_path, "[^/]*$", "")
-    path = path .. relative_path
-    path = string.gsub(path, "([^/]*%./)", function (s)
-        if s ~= "./" then return s else return "" end
-    end)
-    path = string.gsub(path, "/%.$", "/")
-    local reduced
-    while reduced ~= path do
-        reduced = path
-        path = string.gsub(reduced, "([^/]*/%.%./)", function (s)
-            if s ~= "../../" then return "" else return s end
-        end)
-    end
-    path = string.gsub(reduced, "([^/]*/%.%.)$", function (s)
-        if s ~= "../.." then return "" else return s end
-    end)
+    if string.sub(relative_path, 1, 1) == "/" then
+      return remove_dot_components(relative_path) end
+    base_path = base_path:gsub("[^/]*$", "")
+    if not base_path:find'/$' then base_path = base_path .. '/' end
+    local path = base_path .. relative_path
+    path = remove_dot_components(path)
     return path
 end
 
@@ -227,10 +244,14 @@ function _M.absolute(base_url, relative_url)
     else
         base_parsed = _M.parse(base_url)
     end
+    local result
     local relative_parsed = _M.parse(relative_url)
-    if not base_parsed then return relative_url
-    elseif not relative_parsed then return base_url
-    elseif relative_parsed.scheme then return relative_url
+    if not base_parsed then
+        result = relative_url
+    elseif not relative_parsed then
+        result = base_url
+    elseif relative_parsed.scheme then
+        result = relative_url
     else
         relative_parsed.scheme = base_parsed.scheme
         if not relative_parsed.authority then
@@ -248,8 +269,9 @@ function _M.absolute(base_url, relative_url)
                     relative_parsed.path)
             end
         end
-        return _M.build(relative_parsed)
+        result = _M.build(relative_parsed)
     end
+    return remove_dot_components(result)
 end
 
 -----------------------------------------------------------------------------