From a91b59ab5dd2468e3f48079d45f90a9625a29fe3 Mon Sep 17 00:00:00 2001 From: mid-kid Date: Thu, 26 Jul 2018 23:26:14 +0200 Subject: [PATCH] Remove a documented bug that's not really a bug I mean, technically, being able to read beyond a data table's size is bad practice, but there's so many cases of this that it's not worth mentioning. For most of these cases, at least, it's safe to assume the index won't ever get high enough to surpass such a table's length, because it's either hardcoded or decided by the game without the use of uncontrollable data. As such, they don't expose any actual bugs. --- docs/bugs_and_glitches.md | 30 ------------------------- engine/events/bug_contest/contest_2.asm | 3 --- 2 files changed, 33 deletions(-) diff --git a/docs/bugs_and_glitches.md b/docs/bugs_and_glitches.md index 1b20d560d..b2cf35ee7 100644 --- a/docs/bugs_and_glitches.md +++ b/docs/bugs_and_glitches.md @@ -55,7 +55,6 @@ These are known bugs and glitches in the original Pokémon Crystal game: code th - [`LoadSpriteGFX` does not limit the capacity of `UsedSprites`](#loadspritegfx-does-not-limit-the-capacity-of-usedsprites) - [`ChooseWildEncounter` doesn't really validate the wild Pokémon species](#choosewildencounter-doesnt-really-validate-the-wild-pokémon-species) - [`TryObjectEvent` arbitrary code execution](#tryobjectevent-arbitrary-code-execution) -- [`CheckBugContestContestantFlag` can read beyond its data table](#checkbugcontestcontestantflag-can-read-beyond-its-data-table) - [`ClearWRAM` only clears WRAM bank 1](#clearwram-only-clears-wram-bank-1) @@ -1491,35 +1490,6 @@ In [engine/overworld/events.asm](/engine/overworld/events.asm): ``` -## `CheckBugContestContestantFlag` can read beyond its data table - -In [engine/events/bug_contest/contest_2.asm](/engine/events/bug_contest/contest_2.asm): - -```asm -CheckBugContestContestantFlag: -; Checks the flag of the Bug Catching Contestant whose index is loaded in a. - -; Bug: If a >= NUM_BUG_CONTESTANTS when this is called, -; it will read beyond the table. - - ld hl, BugCatchingContestantEventFlagTable - ld e, a - ld d, 0 - add hl, de - add hl, de - ld e, [hl] - inc hl - ld d, [hl] - ld b, CHECK_FLAG - call EventFlagAction - ret - -INCLUDE "data/events/bug_contest_flags.asm" -``` - -However, `a < NUM_BUG_CONTESTANTS` should always be true, so in practice this is not a problem. - - ## `ClearWRAM` only clears WRAM bank 1 In [home/init.asm](/home/init.asm): diff --git a/engine/events/bug_contest/contest_2.asm b/engine/events/bug_contest/contest_2.asm index 9cf70a03e..ddfad8644 100644 --- a/engine/events/bug_contest/contest_2.asm +++ b/engine/events/bug_contest/contest_2.asm @@ -58,9 +58,6 @@ SelectRandomBugContestContestants: CheckBugContestContestantFlag: ; Checks the flag of the Bug Catching Contestant whose index is loaded in a. -; Bug: If a >= NUM_BUG_CONTESTANTS when this is called, -; it will read beyond the table. - ld hl, BugCatchingContestantEventFlagTable ld e, a ld d, 0