Entry 299

A Data Bug drawn and held at half its HP: the area's entry copy, virusFlag on the character

2026-09-28battlerender

Filescrates/piney-battle/src/tables.rscrates/piney-battle/src/enemy_ai.rscrates/piney-battle/src/races.rscrates/piney-battle/src/world.rscrates/piney-world/src/combat/cast.rscrates/piney-world/src/field_world.rscrates/piney-game/src/session/tests/data_bug.rstools/test_battle_spawn_rs.pydocs/engine/battle.md

Reported in play (INF, Mistral's side quest, a dungeon's B3): a Data Bug (an enemyTbl row of type 0x40) fought with no model on screen, the hits and "DATA DRAIN OK" shown, and one hit of 1813 took its HP down; normal hits could finish it.

What the game does

The 45 middle-boss rows (type 0x40: 54, 55, ... 115, ... 302 on INF) have no animation table of their own and a file named with a fourth letter X (row 115 EETX, base form 113 EET1).

• Loading. ccAddRequestFileListEntry (INF GCMN.PRG:0x0042f5a0) copies the base form's (base.gold) entry.anm (+0x80 of the row), clut (+0x88, 30 bytes) and fileList (+0xa8, +0xac) into a registered middle boss's entry, loads that file and the name with its fourth letter X. initEntryCCS (0x0042feb0) sets ccsc and ccsc2 from them. The same function is at MUT 0x00444f88, OUT 0x0043fdf8, QUA 0x00332708 (its 0x40 test and the +0x80 copy).
• The models. initEnemyCCS (0x00432fc0) makes CMP_trall of ccsc playing anm[6] (ANM_eet1nut0), and for a middle boss (the only caller of ccCheckMiddleBoss, 0x004330c4) CMP_trall of ccsc2 playing the same name with its eighth letter x (ANM_eetxnut0, in eetx), shadow off. dispEnemy (0x004348b0) draws that one on layer 5, then the body.
• The HP rule. initEnemyCCS sets virusFlag (ccEnemy +0x250 bit 6, 0x004331f8-0x0043320c) when the row's maxPP is not -1. affectEnemy (0x00433c0c-0x00433c8c) is the only reader: damage and poison take d / 10 (toward 0), and HP below maxHP / 2 is set to maxHP / 2. The fly font (0x00433bb8) shows the whole d. CalcBattleDamage (0x0056d910) and the skill paths have no case for type 0x40 (no other function tests the bit or calls ccCheckMiddleBoss), so the numbers are ordinary and the HP stops at half: row 115 (20169 HP) at 10084. Only Data Drain after the protect breaks ends it. Nothing restores HP, and the name's garbling is the row's own name text.

Why the port differed

• The battle tables kept the disc's empty anm for the middle bosses (the spawn check's interpreter read EE address 0xb4 as empty too, since it never ran the loading's copy). races::init_enemy set the clip "", Cast::set found no look with that clip, no actor was made, and nothing was drawn; the skill list was empty, so it never attacked.
• An actor's look was the first look holding its clip: row 115 would have drawn as 113 (no second model; rows sharing a file with an earlier row took its palette). The second model's clip was played on the body's own file, which lacks the x clips.
• virusFlag was set on the port's Enemy, but affect_enemy reads the character's enemy_flags (the same ccEnemy word), which nothing set.

The fix

• Tables::of applies the loading's copy (with_base_forms).
• init_enemy sets enemy_flag::VIRUS on the character with virus_flag.
• A new World::enemy_ccs(who, row) (default nothing), called first in races::init_enemy: the field's Cast::enemy_ccs makes the actor from the row's own look and keeps the second clump's file (second_file), which the second slot's SetAnm and _AnimateForward now use.
• FieldWorld::put_enemy (tests and tools) puts an enemy as an event's entry 5 does, loading the row's look (Looks::add_enemies, split out of load_looks).
• tools/test_battle_spawn_rs.py does the loading's copy in its scene, so its race check covers the middle bosses with their clips.

Tests: middle_bosses_take_their_base_forms_entry and a_data_bug_is_not_beaten_by_damage (piney-battle) fail without the fix (no clips; no virus bit). a_data_bug_is_drawn_and_not_beaten_by_damage (session) puts row 115 in a field, sees it drawn with both models on 1154 frames and the console's kill every 20 frames leave it at 10084; without the fix it fails with no actor. test_battle_spawn_rs.py bulk 300 of race, entry and frame_enemies: 0 mismatches (all 299 rows); the piney-game suite passes (163).