From b820d3917c7e8200176483b30da6b6ea08f0aba1 Mon Sep 17 00:00:00 2001
From: spiritsnails <307422241+spiritsnails@users.noreply.github.com>
Date: Sat, 1 Aug 2026 19:13:03 -0600
Subject: [PATCH] fixing failed tests/harnesses

---
 src/core/FixedStep.lua                    | 21 +++++++++++++++++----
 tests/engine/rebind_swap_clear_bug589.lua | 11 +++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/core/FixedStep.lua b/src/core/FixedStep.lua
index 39cd980f..fe773e27 100644
--- a/src/core/FixedStep.lua
+++ b/src/core/FixedStep.lua
@@ -10,6 +10,7 @@ local MAX_ACCUM = 0.25 -- avoid spiral of death after a stall
 function FixedStep:init(callback)
   self.accum = 0
   self.callback = callback
+  self.suppressCatchup = false
 end
 
 -- The anti-spiral clamp doubles as a steps-per-frame ceiling (0.25s = 15
@@ -20,6 +21,16 @@ end
 FixedStep.maxAccum = MAX_ACCUM
 
 function FixedStep:update(dt)
+  -- A hitch's oversized dt lands on the frame AFTER discardCatchup was
+  -- called (the hitch itself already ran inside the current step); absorb
+  -- that one frame as a single step instead of the normal accumulator so
+  -- the burst it would otherwise release doesn't play out as a slide.
+  if self.suppressCatchup then
+    self.suppressCatchup = false
+    self.accum = 0
+    self.callback(self.STEP)
+    return
+  end
   self.accum = math.min(self.accum + dt, self.maxAccum or MAX_ACCUM)
   while self.accum >= self.STEP do
     self.accum = self.accum - self.STEP
@@ -27,12 +38,14 @@ function FixedStep:update(dt)
   end
 end
 
--- Drop any pending catch-up steps.  A hitch inside one logic step (map
--- seam setMap / song start) makes the next real-time dt huge; without this
--- the while-loop above would advance many walk frames before the next
--- draw, which looks like a slide with no leg animation (issue #93).
+-- Drop any pending catch-up steps and arm the one-frame clamp above.  A
+-- hitch inside one logic step (map seam setMap / song start) makes the
+-- next real-time dt huge; without this the while-loop above would advance
+-- many walk frames before the next draw, which looks like a slide with no
+-- leg animation (issue #93).
 function FixedStep:discardCatchup()
   self.accum = 0
+  self.suppressCatchup = true
 end
 
 return FixedStep
diff --git a/tests/engine/rebind_swap_clear_bug589.lua b/tests/engine/rebind_swap_clear_bug589.lua
index 8efd19d0..0e49d03d 100644
--- a/tests/engine/rebind_swap_clear_bug589.lua
+++ b/tests/engine/rebind_swap_clear_bug589.lua
@@ -17,6 +17,7 @@ love = love or require("tests.love_stub")
 
 local Input = require("src.core.Input")
 local Strings = require("src.core.Strings")
+local Timing = require("src.core.Timing")
 local BindingsMenu = require("src.ui.BindingsMenu")
 
 -- same doubles as rebind_capture_bug510: a stack the menu can pop itself
@@ -45,6 +46,14 @@ local function press(state, btn)
   state.game.input.queue = {}
 end
 
+-- ChoiceBox now holds YES/NO answers on screen for Timing.YES_NO_ANSWER
+-- frames before it commits and pops (DisplayTwoOptionMenu's 15-frame hold,
+-- #GH-627 timing parity); a bare press only arms the choice, so answering
+-- it needs the hold run out before the pop/commit is visible.
+local function settleChoice(state)
+  for _ = 1, Timing.YES_NO_ANSWER do state:update(1 / 60) end
+end
+
 -- rows are BindingsMenu's BUTTONS order
 local ROW_A, ROW_B, ROW_SELECT = 5, 6, 8
 
@@ -146,6 +155,7 @@ eq(bm.footer, Strings("RESET ALL BINDINGS?"),
 
 -- the box starts on NO: a bare A press must keep the overlay
 press(box, "a")
+settleChoice(box)
 eq(game.stack:top(), bm, "answering pops the box")
 check(game.save.options.bindings ~= nil, "NO keeps the bindings (defaultNo)")
 eq(bm.items[ROW_A].right, "P/B", "and the rows keep showing them")
@@ -155,6 +165,7 @@ press(bm, "start")
 box = game.stack:top()
 press(box, "up")
 press(box, "a")
+settleChoice(box)
 check(game.save.options.bindings == nil, "YES clears options.bindings (#589)")
 eq(bm.items[ROW_A].right, "Z/A", "the A row reads its default again")
 eq(bm.items[ROW_B].right, "X/B", "so does the B row the swap had touched")