From 33fdffd2502fef3784fd608c323706d608c315bc Mon Sep 17 00:00:00 2001
From: Jad Dayoub <jad.taim2003@gmail.com>
Date: Tue, 28 Jul 2026 17:31:15 +0200
Subject: [PATCH] [ntuple] Fix kReal32Quant decoding for 32-bit values Avoid
 5-bit masking of JS shift counts, which made divisor 0 at nbits = 32. Cast
 res to Uint32, s.t. bit 31 is not interpreted as sign bit.

---
 modules/rntuple.mjs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/modules/rntuple.mjs b/modules/rntuple.mjs
index 84443bb71..251d33301 100644
--- a/modules/rntuple.mjs
+++ b/modules/rntuple.mjs
@@ -870,7 +870,7 @@ class ReaderItem {
          case kReal32Quant:
             this.nbits = this.column.bitsOnStorage;
             if (!this.buf) {
-               this.factor = (this.column.maxValue - this.column.minValue) / ((1 << this.nbits) - 1);
+               this.factor = (this.column.maxValue - this.column.minValue) / (2 ** this.nbits - 1);
                this.min = this.column.minValue;
             }
 
@@ -899,7 +899,7 @@ class ReaderItem {
                   this.buf.setUint32(0, res << (32 - this.nbits), true);
                   obj[this.name] = this.buf.getFloat32(0, true);
                } else
-                  obj[this.name] = res * this.factor + this.min;
+                  obj[this.name] = (res >>> 0) * this.factor + this.min; // convert res to Uint32
             };
             break;
          case kInt64: