From 0e3f7c44b296f98c7bf5e44008f922701a494a28 Mon Sep 17 00:00:00 2001
From: "James D. Forrester" <jforrester@wikimedia.org>
Date: Tue, 9 Aug 2022 17:39:53 -0400
Subject: [PATCH] inEventSample: Avoid invalid character warning from sampling
 code, hash into hex

Bug: T314896
Change-Id: I377bbe54686fdb9d765543320aef14a99ee2cd7f
---
 includes/Hooks.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/includes/Hooks.php b/includes/Hooks.php
index dc30311f..09a2ac27 100644
--- a/includes/Hooks.php
+++ b/includes/Hooks.php
@@ -97,8 +97,12 @@ class Hooks implements
 		// Sample 6.25%
 		$samplingRate = $this->config->has( 'WMESchemaEditAttemptStepSamplingRate' ) ?
 			$this->config->get( 'WMESchemaEditAttemptStepSamplingRate' ) : 0.0625;
+
+		// (T314896) Convert whatever we've been given to a string of hex, as that's what EL needs
+		$hexValue = hash( 'md5', $sessionId, false );
+
 		$inSample = EventLogging::sessionInSample(
-			(int)( 1 / $samplingRate ), $sessionId
+			(int)( 1 / $samplingRate ), $hexValue
 		);
 		return $inSample;
 	}