From c58a6d6115dbaaa1a1bc68839637c33007cf4f66 Mon Sep 17 00:00:00 2001
From: 94xhn <87560781+94xhn@users.noreply.github.com>
Date: Fri, 17 Jul 2026 01:33:52 +0800
Subject: [PATCH] Fix off-by-one OOB table read in Sample::next()

Sample::next() used a strict > comparison (phase_fractional >
endpos_fractional) to decide when to wrap/finish playback, while
isPlaying() already treats phase_fractional == endpos_fractional as
finished (using <). When phase lands exactly on endpos_fractional
(which happens deterministically for many freq/table-size ratios),
next() would compute index = endpos_fractional >> SAMPLE_F_BITS ==
NUM_TABLE_CELLS, one past the last valid table entry, and read (and
for INTERP_LINEAR, also read index+1) out of bounds before wrapping
on the following call.

Change the comparison to >= so next() treats phase == endpos as
finished/wrap, consistent with isPlaying(), eliminating the
out-of-bounds table read.
---
 Sample.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sample.h b/Sample.h
index 30a2d60ef..2cb9f8a47 100644
--- a/Sample.h
+++ b/Sample.h
@@ -164,7 +164,7 @@ class Sample
 	inline
 	int8_t next() { // 4us
 
-		if (phase_fractional>endpos_fractional){
+		if (phase_fractional>=endpos_fractional){
 			if (looping) {
 				phase_fractional = startpos_fractional + (phase_fractional - endpos_fractional);
 			}else{