[Ketho]

When you shift-leftclick a header item in the TradeSkill window (without any addons enabled)

It will call C_TradeSkillUI.GetRecipeLink() and pass a nil value

https://github.com/Gethe/wow-ui-sour....xml#L201-L211

Date: 2016-08-01 21:20:39
ID: 1
Error occured in: Global
Count: 1
Message: [string "*:OnClick"] line 2:
   Usage: GetRecipeLink(recipeID)
Debug:
   [C]: GetRecipeLink()
   [string "*:OnClick"]:2:
      [string "*:OnClick"]:1
Locals:
(*temporary) = nil

AddOns:
  Swatter, v5.21f.5579 (SanctimoniousSwamprat)
  BlizRuntimeLib_enUS v7.0.3.70000 <none>
  (ck=59)

Would something like this work?

<OnClick>
	if IsModifiedClick() then
		if not self.isHeader then
			HandleModifiedItemClick(C_TradeSkillUI.GetRecipeLink(self.tradeSkillInfo.recipeID));
		end
	else
		if self.isHeader then
			self:GetParent():GetParent():OnHeaderButtonClicked(self, self.tradeSkillInfo, button);
		else
			self:GetParent():GetParent():OnRecipeButtonClicked(self, self.tradeSkillInfo, button);
		end
	end
</OnClick>