From e339d72df60da938ce294d898476f3330c8a44aa Mon Sep 17 00:00:00 2001
From: Leo Gavilieau <xmoo@privacyrequired.com>
Date: Sun, 21 May 2023 22:25:49 +0200
Subject: [PATCH] fix: Fix link filter for external urls

---
 utils/link-filter.da.lua    | 21 +++++++++++++++++++--
 utils/link-filter.en.lua    | 21 +++++++++++++++++++--
 utils/link-filter.pt-BR.lua | 21 +++++++++++++++++++--
 3 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/utils/link-filter.da.lua b/utils/link-filter.da.lua
index 92be730..30c030c 100644
--- a/utils/link-filter.da.lua
+++ b/utils/link-filter.da.lua
@@ -1,6 +1,23 @@
 lang = "da"
 
+local function stringstarts(String,Start)
+  return string.sub(String,1,string.len(Start))==Start
+end
+
 function Link(el)
-  el.target = "/" .. lang .. el.target
-  return el
+  --[[
+    It runs these checks and if any succeed then it runs this action and returns the link, preventing the others from running.
+    1. Check if its a URL scheme, if so then change nothing
+    2. Check if its a ../ url, which means remove language parameter
+    3. Change URL irregardless
+  ]]--
+  if el.target:find('://') then
+    return el
+  elseif stringstarts(el.target, '../') then
+    el.target = el.target:sub(3)
+    return el
+  else 
+    el.target = "/" .. lang .. el.target
+    return el
+  end
 end
\ No newline at end of file
diff --git a/utils/link-filter.en.lua b/utils/link-filter.en.lua
index c5deeb4..f4d4fa3 100644
--- a/utils/link-filter.en.lua
+++ b/utils/link-filter.en.lua
@@ -1,6 +1,23 @@
 lang = "en"
 
+local function stringstarts(String,Start)
+  return string.sub(String,1,string.len(Start))==Start
+end
+
 function Link(el)
-  el.target = "/" .. lang .. el.target
-  return el
+  --[[
+    It runs these checks and if any succeed then it runs this action and returns the link, preventing the others from running.
+    1. Check if its a URL scheme, if so then change nothing
+    2. Check if its a ../ url, which means remove language parameter
+    3. Change URL irregardless
+  ]]--
+  if el.target:find('://') then
+    return el
+  elseif stringstarts(el.target, '../') then
+    el.target = el.target:sub(3)
+    return el
+  else 
+    el.target = "/" .. lang .. el.target
+    return el
+  end
 end
\ No newline at end of file
diff --git a/utils/link-filter.pt-BR.lua b/utils/link-filter.pt-BR.lua
index cad9188..4e599f5 100644
--- a/utils/link-filter.pt-BR.lua
+++ b/utils/link-filter.pt-BR.lua
@@ -1,6 +1,23 @@
 lang = "pt-BR"
 
+local function stringstarts(String,Start)
+  return string.sub(String,1,string.len(Start))==Start
+end
+
 function Link(el)
-  el.target = "/" .. lang .. el.target
-  return el
+  --[[
+    It runs these checks and if any succeed then it runs this action and returns the link, preventing the others from running.
+    1. Check if its a URL scheme, if so then change nothing
+    2. Check if its a ../ url, which means remove language parameter
+    3. Change URL irregardless
+  ]]--
+  if el.target:find('://') then
+    return el
+  elseif stringstarts(el.target, '../') then
+    el.target = el.target:sub(3)
+    return el
+  else 
+    el.target = "/" .. lang .. el.target
+    return el
+  end
 end
\ No newline at end of file