From d2126c8a2ee5e5cf4652c6b9d0234368180f348d Mon Sep 17 00:00:00 2001
From: Chris Cannam <cannam@all-day-breakfast.com>
Date: Thu, 30 Jun 2022 09:32:39 +0100
Subject: [PATCH] Fix array overrun

---
 src/finer/Guide.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/finer/Guide.h b/src/finer/Guide.h
index a7e5538..8162b01 100644
--- a/src/finer/Guide.h
+++ b/src/finer/Guide.h
@@ -458,12 +458,17 @@ protected:
     }
 
     double descendToValley(double f, const double *const magnitudes) const {
+        if (f == 0.0 || f == m_parameters.sampleRate/2.0) {
+            // These are special cases
+            return f;
+        }
         int b = binForFrequency(f, m_configuration.classificationFftSize,
                                 m_parameters.sampleRate);
+        int n = m_configuration.classificationFftSize/2;
         for (int i = 0; i < 3; ++i) {
-            if (magnitudes[b+1] < magnitudes[b]) {
+            if (b < n && magnitudes[b+1] < magnitudes[b]) {
                 ++b;
-            } else if (magnitudes[b-1] < magnitudes[b]) {
+            } else if (b > 0 && magnitudes[b-1] < magnitudes[b]) {
                 --b;
             } else {
                 break;