From feb276ccfaab05458f96cfd24b7accf5135c0443 Mon Sep 17 00:00:00 2001
From: James Grugett <jahooma@gmail.com>
Date: Tue, 5 Apr 2022 15:16:51 -0500
Subject: [PATCH] Defensive break in binary search

---
 common/calculate-cpmm.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/common/calculate-cpmm.ts b/common/calculate-cpmm.ts
index baadb31f..ab6fd3c5 100644
--- a/common/calculate-cpmm.ts
+++ b/common/calculate-cpmm.ts
@@ -151,6 +151,8 @@ function calculateCpmmShareValue(
   let kGuess = 0
   while (Math.abs(k - kGuess) > 0.00000000001) {
     mid = lowAmount + (highAmount - lowAmount) / 2
+    if (mid === lowAmount || mid === highAmount) break
+
     kGuess = sellSharesK(pool.YES, pool.NO, p, shares, outcome, mid)
     if (kGuess < k) {
       highAmount = mid