item: dress GameTooltip:GetItem() name with random suffix

GameTooltip:GetItem() resolved the CGItem and built the suffixed link via
Item::Link::FromCGItem, but returned the base ItemStats name beside it --
so name and link disagreed ("Iridium Chain" vs "[Iridium Chain of the
Owl]"). The old comment claimed the engine didn't expose the dressed name
as a separate string; it does, via the same builder the link uses.

Extract that builder into a shared Item::Link::NameFromCGItem helper
(next to FromCGItem, wrapping FUN_ITEM_BUILD_INSTANCE_NAME) and use it in
both GetItem and C_Item.GetItemName so the returned name matches the link
and modern behavior. Verified in-game: GetItem() now returns "Iridium
Chain of the Owl" alongside its matching link.

Left the base-name reads that are correct as-is: itemID-only paths (mail,
cursor-by-id, GetItemInfo, equipment-set missing items) have no instance,
and the by-name *matching* in IsEquippedItem / bag lookups compares
against a caller string (a separate semantics question).

Author: brues-code

src/item/Link.cpp

@@ -27,6 +27,9 @@ namespace {
 
 using BuildItemLink_t = const char *(__fastcall *)(const void *cgItem);
 
+using BuildInstanceName_t = void(__thiscall *)(const void *cgItem, char *out,
+                                               unsigned outSize);
+
 // Cached ItemStats record lookup. Same `_GetRecord` pattern the rest of
 // the codebase uses; passes a noop NULL callback so no SMSG fires for
 // uncached items — caller treats "not cached" as a clean failure.
@@ -50,6 +53,16 @@ const char *FromCGItem(const uint8_t *cgItem) {
     return fn(cgItem);
 }
 
+bool NameFromCGItem(const uint8_t *cgItem, char *out, size_t outSize) {
+    if (cgItem == nullptr || out == nullptr || outSize == 0)
+        return false;
+    out[0] = '\0';
+    auto fn = reinterpret_cast<BuildInstanceName_t>(
+        Offsets::FUN_ITEM_BUILD_INSTANCE_NAME);
+    fn(cgItem, out, static_cast<unsigned>(outSize));
+    return out[0] != '\0';
+}
+
 bool BasicFromItemID(uint32_t itemID, char *out, size_t outSize) {
     if (out == nullptr || outSize == 0)
         return false;

src/item/Link.h

@@ -29,6 +29,17 @@ namespace Item::Link {
 // produce for the same slot.
 const char *FromCGItem(const uint8_t *cgItem);
 
+// Writes the item's per-instance decorated *display name* into `out` —
+// the same `[Name]` the engine stamps into `FromCGItem`'s link, e.g.
+// "Iridium Chain of the Owl" (or the base name when the instance carries
+// no random suffix). Reads the suffix ID off the CGItem descriptor
+// (`+0x98`) and formats it through the engine's own name builder
+// (`FUN_ITEM_BUILD_INSTANCE_NAME`). Returns false (and leaves `out`
+// empty) for a null item or an empty build result, so callers can fall
+// back to the base ItemStats name. Use whenever a name is returned
+// alongside a `FromCGItem` link, so the two agree.
+bool NameFromCGItem(const uint8_t *cgItem, char *out, size_t outSize);
+
 // Builds a basic itemID-only hyperlink (`"|cffRRGGBB|Hitem:N:0:0:0|h[Name]|h|r"`)
 // into `out` from the cached ItemStats record for `itemID`. No
 // enchant / random-suffix decoration — use this when the caller has

src/item/Name.cpp

@@ -16,6 +16,7 @@
 #include "item/Arg.h"
 #include "item/Data.h"
 #include "item/ID.h"
+#include "item/Link.h"
 #include "item/Location.h"
 
 #include <cstdint>
@@ -56,27 +57,13 @@ int PushNameForItemID(void *L, int itemID) {
     return 1;
 }
 
-// Engine's per-instance item-name builder: `__thiscall(CGItem *this,
-// char *outBuf, uint outSize)`. Reads the instance's random-suffix ID off
-// the descriptor (+0x98) and writes the decorated display name
-// ("Ethereum Torque of the Sorcerer"), or the base name when there's no
-// suffix. Same builder the item-link builder uses for the bracketed name,
-// so this matches `GetItemLink`'s name and modern `C_Item.GetItemName`.
-using BuildInstanceName_t = void(__thiscall *)(const void *cgItem, char *out,
-                                               unsigned outSize);
-
-// Pushes the suffix-decorated display name for a resolved `CGItem`.
-// Returns 0 (pushes nothing) for a null item or an empty build result,
-// so the caller can fall back to the base-name-by-itemID path.
+// Pushes the suffix-decorated display name for a resolved `CGItem` via
+// the shared engine name builder. Returns 0 (pushes nothing) for a null
+// item or an empty build result, so the caller can fall back to the
+// base-name-by-itemID path.
 int PushInstanceName(void *L, const uint8_t *cgItem) {
-    if (cgItem == nullptr)
-        return 0;
     char buf[128];
-    buf[0] = '\0';
-    auto fn = reinterpret_cast<BuildInstanceName_t>(
-        Offsets::FUN_ITEM_BUILD_INSTANCE_NAME);
-    fn(cgItem, buf, sizeof(buf));
-    if (buf[0] == '\0')
+    if (!Item::Link::NameFromCGItem(cgItem, buf, sizeof(buf)))
         return 0;
     Game::Lua::PushString(L, buf);
     return 1;

src/item/Tooltip.cpp

@@ -220,24 +220,19 @@ static int __fastcall Script_GameTooltipGetItem(void *L) {
             const char *link = Item::Link::FromCGItem(
                 static_cast<const uint8_t *>(cgItem));
             if (link != nullptr && *link != '\0') {
-                // Engine's link builder also writes the dressed
-                // (random-suffixed) name into the link's `[Name]`
-                // slot; pull it out by reading the cached base name
-                // for the return value. The engine doesn't expose
-                // the dressed name as a separate string, so we
-                // return the base name — matches modern semantics
-                // where (name, link) name is the cached display name
-                // and the link is the full hyperlink.
-                const uint8_t *record = PeekItemRecord(static_cast<uint32_t>(itemID));
-                if (record != nullptr) {
-                    const char *name = *reinterpret_cast<const char *const *>(
-                        record + Offsets::OFF_ITEMSTATS_NAME);
-                    if (name != nullptr && *name != '\0') {
-                        Game::Lua::PushString(L, name);
-                        Game::Lua::PushString(L, link);
-                        Game::Lua::PushNumber(L, static_cast<double>(itemID));
-                        return 3;
-                    }
+                // Return the dressed (random-suffixed) name the engine
+                // wrote into the link's `[Name]` slot — built off the same
+                // CGItem via Item::Link::NameFromCGItem — so the returned
+                // name agrees with the link ("Iridium Chain of the Owl",
+                // not the base "Iridium Chain") and matches modern
+                // GameTooltip:GetItem() on suffixed items.
+                char name[128];
+                if (Item::Link::NameFromCGItem(
+                        static_cast<const uint8_t *>(cgItem), name, sizeof(name))) {
+                    Game::Lua::PushString(L, name);
+                    Game::Lua::PushString(L, link);
+                    Game::Lua::PushNumber(L, static_cast<double>(itemID));
+                    return 3;
                 }
             }
         }