From eafff58a54993c5cada724894630a8484ae324bc Mon Sep 17 00:00:00 2001
From: atm-greg <gregory.blemand@atm-consulting.fr>
Date: Fri, 6 Mar 2020 11:30:45 +0100
Subject: [PATCH] fix countable warning

---
 htdocs/core/class/dolgraph.class.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/htdocs/core/class/dolgraph.class.php b/htdocs/core/class/dolgraph.class.php
index 460b425b8aa..d4eb100f221 100644
--- a/htdocs/core/class/dolgraph.class.php
+++ b/htdocs/core/class/dolgraph.class.php
@@ -1189,7 +1189,7 @@ class DolGraph
 			$oldstacknum = -1;
 			while ($i < $nblot)	// Loop on each serie
 			{
-				if (count($arrayofgroupslegend[$i]) > 0) {	// We used a 'group by'
+				if (is_array($arrayofgroupslegend[$i]) && count($arrayofgroupslegend[$i]) > 0) {	// We used a 'group by'
 					// If we change the stack
 					$newcolor = $this->datacolor[$arrayofgroupslegend[$i]['stacknum']];
 					if ($oldstacknum == -1 || $arrayofgroupslegend[$i]['stacknum'] != $oldstacknum) {