Fix invalid mod parsing for mods that grant skills (#10174)

* Fix invalid mod parsing on mods that grant skills

* add regression test for invalid mod parsing involving grantedExtraSkill

* Stop skill granting mods from scaling

---------

Co-authored-by: LocalIdentity <localidentity2@gmail.com>

Author: Trifall

spec/System/TestItemParse_spec.lua

@@ -1358,5 +1358,44 @@ describe("TestAdvancedItemParse #item", function()
 			assert.equal(27, spellCrit())
 			assert.equal(8, spellDamage())
 		end)
+		it("does not scale modifiers that grant skills", function()
+			local item = new("Item", [[
+				Item Class: Rings
+				Rarity: Rare
+				Plague Knuckle
+				Helical Ring
+				--------
+				Item Level: 84
+				--------
+				{ Implicit Modifier }
+				50% increased Suffix Modifier magnitudes
+				--------
+				{ Suffix Modifier "of !!UNPARSEABLE!!"  — 50% Increased }
+				Grants Level 20 Aspect of !!UNPARSEABLE!! Skill
+				{ Suffix Modifier "of the Spider"  — 50% Increased }
+				Grants Level 20 Aspect of the Spider Skill
+				--------
+			]])
+			assert.truthy(item.base)
+			local found = 0
+			local foundExtraSkill = false
+			for _, modLine in ipairs(item.explicitModLines) do
+				if modLine.line:find("Grants Level", 1, true) then
+					found = found + 1
+					assert.matches("Level 20", itemLib.formatModLine(modLine))
+					for _, mod in ipairs(modLine.modList) do
+						if mod.name == "ExtraSkill" then
+							foundExtraSkill = true
+							assert.equals(20, mod.value.level)
+						end
+					end
+					if modLine.line:find("UNPARSEABLE", 1, true) then
+						assert.truthy(modLine.extra)
+					end
+				end
+			end
+			assert.equals(2, found)
+			assert.is_true(foundExtraSkill)
+		end)
 	end)
 end)

src/Classes/Item.lua

@@ -1394,6 +1394,18 @@ function ItemClass:ParseRaw(raw, rarity, highQuality)
 						if mod.variantList and (self:GetModLineVariantCount(mod) == 0) then
 							goto modMagnitudeContinue
 						end
+						-- Modifiers that grant skills are not affected by modifier magnitude.
+						local grantsSkill = false
+						for _, parsedMod in ipairs(mod.modList) do
+							if parsedMod.name == "ExtraSkill" then
+								grantsSkill = true
+								break
+							end
+						end
+						if mod.extra and not grantsSkill then
+							local line = mod.line:lower()
+							grantsSkill = line:match("^grants level %d+ ") or line:match("^grants %D+$")
+						end
 						-- Create a fast lookup table for all provided tags
 						local tagLookup = {}
 						for _, curTag in ipairs(mod.modTags) do
@@ -1414,7 +1426,7 @@ function ItemClass:ParseRaw(raw, rarity, highQuality)
 						if modMagnitudeMod.anyTags and not (tagLookup[modMagnitudeMod.anyTags[1]] or tagLookup[modMagnitudeMod.anyTags[2]]) then
 							match = false
 						end
-						if match and not mod.unscalable then
+						if match and not mod.unscalable and not grantsSkill then
 							if modMagnitudeMod.multiplier then
 								mod.valueScalar = (mod.valueScalar or 1) * modMagnitudeMod.multiplier
 							else
@@ -1424,9 +1436,11 @@ function ItemClass:ParseRaw(raw, rarity, highQuality)
 						if mod.valueScalar and mod.valueScalar ~= 1 then
 							local rangedLine = itemLib.applyRange(mod.line, mod.range or 1, mod.valueScalar, 1)
 							local modList, extra = modLib.parseMod(rangedLine)
-							mod.displayValueScalar = 1
-							mod.modList = modList
-							mod.extra = extra
+							if modList then
+								mod.displayValueScalar = 1
+								mod.modList = modList
+								mod.extra = extra
+							end
 						end
 						::modMagnitudeContinue::
 					end