File 0005-libcamera-simple-Prevent-division-by-zero-in-BLC.patch of Package libcamera

From ef0b475f471e114044a7fbacf13bb16b5d362def Mon Sep 17 00:00:00 2001
From: Milan Zamazal <mzamazal@redhat.com>
Date: Thu, 21 Aug 2025 15:41:41 +0200
Subject: [PATCH 05/17] libcamera: simple: Prevent division by zero in BLC

When there are no values in the histogram, BLC simple IPA can crash on
division by zero.  We cannot get anything meaningful in such a case
anyway, let's simply return from `process()' then.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
---
 src/ipa/simple/algorithms/blc.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ipa/simple/algorithms/blc.cpp b/src/ipa/simple/algorithms/blc.cpp
index 8c1e9ed08..71731c6f6 100644
--- a/src/ipa/simple/algorithms/blc.cpp
+++ b/src/ipa/simple/algorithms/blc.cpp
@@ -77,6 +77,11 @@ void BlackLevel::process(IPAContext &context,
 	constexpr float ignoredPercentage = 0.02;
 	const unsigned int total =
 		std::accumulate(begin(histogram), end(histogram), 0);
+	if (total == 0) {
+		LOG(IPASoftBL, Debug) << "Not guessing black level, histogram is empty";
+		return;
+	};
+
 	const unsigned int pixelThreshold = ignoredPercentage * total;
 	const unsigned int histogramRatio = 256 / SwIspStats::kYHistogramSize;
 	const unsigned int currentBlackIdx =
-- 
2.50.1