luci-base: fix rendering of 404 HTML error template

This 404 error template rendering has been broken for a long time due to bad
function environment level in luci.template when invoking the rendering from
the toplevel dispatcher context.

Fix this issue by adding a local function indirection, essentially adding an
additional stack frame.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/modules/luci-base/luasrc/dispatcher.lua b/modules/luci-base/luasrc/dispatcher.lua
index fc497ca..5fc2b80 100644 (file)
--- a/modules/luci-base/luasrc/dispatcher.lua
+++ b/modules/luci-base/luasrc/dispatcher.lua
@@ -75,11 +75,16 @@ function error404(message)
        http.status(404, "Not Found")
        message = message or "Not Found"
 
-       require("luci.template")
-       if not util.copcall(luci.template.render, "error404") then
+       local function render()
+               local template = require "luci.template"
+               template.render("error404")
+       end
+
+       if not util.copcall(render) then
                http.prepare_content("text/plain")
                http.write(message)
        end
+
        return false
 end