Profession filter dropdowns can trigger a C stack overflow

[Meorawr]

Opening profession windows in Classic can trigger C stack overflow errors when setting up the item subclass filter dropdown.

Details

1. The TradeSkillFrame_SetupSubClassDropdown function calls SetTradeSkillSubClassFilter. This appears to trigger the TRADE_SKILL_UPDATE event to fire.
2. The handler for that event calls TradeSkillFrame_Update.
3. The TradeSkillFrame_Update function recurses back into TradeSkillFrame_SetupSubClassDropdown.
4. Go back to step 1 :)

This could probably be resolved by just reordering the currentTradeSkillName = name; assignment in TradeSkillFrame_Update to occur before the call into TradeSkillFrame_SetupSubClassDropdown.

Test case

You'll need a character with two professions learned - I've been able to reproduce this with Mining and Blacksmithing learned, and another player has also reproduced this with Mining and Jewelcrafting.

1. Open the professions window.
2. Click "Smelting" to open the Mining professions window.
3. Close the Mining professions window.
4. Click "Blacksmithing" (or Jewelcrafting) to open the other professions window.

At step four you should run into a bunch of C stack overflow errors. An example is provided below:

Message: C stack overflow
Time: Thu Nov  7 00:14:15 2024
Count: 1
Stack: C stack overflow
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:336: in function `TradeSkillFrame_SetSelection'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:135: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>
[string "=[C]"]: in function `SetTradeSkillSubClassFilter'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:50: in function `TradeSkillFrame_SetupSubClassDropdown'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:160: in function `TradeSkillFrame_Update'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:141: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>
[string "=[C]"]: in function `SetTradeSkillSubClassFilter'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:50: in function `TradeSkillFrame_SetupSubClassDropdown'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:160: in function `TradeSkillFrame_Update'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:141: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>
[string "=[C]"]: in function `SetTradeSkillSubClassFilter'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:50: in function `TradeSkillFrame_SetupSubClassDropdown'
...
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:160: in function `TradeSkillFrame_Update'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:141: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>
[string "=[C]"]: in function `SetTradeSkillSubClassFilter'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:50: in function `TradeSkillFrame_SetupSubClassDropdown'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:160: in function `TradeSkillFrame_Update'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:141: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>
[string "=[C]"]: in function `SetTradeSkillSubClassFilter'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:50: in function `TradeSkillFrame_SetupSubClassDropdown'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:160: in function `TradeSkillFrame_Update'
[string "@Interface/AddOns/Blizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua"]:141: in function <...lizzard_TradeSkillUI/Wrath/Blizzard_TradeSkillUI.lua:127>

Locals: id = 2
skillName = "Iron Shield Spike"
skillType = "optimal"
numAvailable = 0
isExpanded = nil
altVerb = nil
creatable = 1
color = <table> {
 b = 0.250000
 font = "GameFontNormalLeftOrange"
 g = 0.500000
 r = 1
}