diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index f267e572ee4..6ee6007088b 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -5671,7 +5671,7 @@ function dol_string_is_good_iso($s)
 	$ok=1;
 	for($scursor=0;$scursor<$len;$scursor++)
 	{
-		$ordchar=ord($s{$scursor});
+		$ordchar=ord($s[$scursor]);
 		//print $scursor.'-'.$ordchar.'<br>';
 		if ($ordchar < 32 && $ordchar != 13 && $ordchar != 10) { $ok=0; break; }
 		if ($ordchar > 126 && $ordchar < 160) { $ok=0; break; }
diff --git a/htdocs/core/lib/json.lib.php b/htdocs/core/lib/json.lib.php
index 4a8f61915b5..423607fb819 100644
--- a/htdocs/core/lib/json.lib.php
+++ b/htdocs/core/lib/json.lib.php
@@ -119,7 +119,7 @@ function _val($val)
 	     */
 	    for ($c = 0; $c < $strlen_var; ++$c) {
 
-	        $ord_var_c = ord($val{$c});
+	        $ord_var_c = ord($val[$c]);
 
 	        switch (true) {
 	            case $ord_var_c == 0x08:
@@ -142,18 +142,18 @@ function _val($val)
 	            case $ord_var_c == 0x2F:
 	            case $ord_var_c == 0x5C:
 	                // double quote, slash, slosh
-	                $ascii .= '\\'.$val{$c};
+	                $ascii .= '\\'.$val[$c];
 	                break;
 
 	            case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
 	                // characters U-00000000 - U-0000007F (same as ASCII)
-	                $ascii .= $val{$c};
+	                $ascii .= $val[$c];
 	                break;
 
 	            case (($ord_var_c & 0xE0) == 0xC0):
 	                // characters U-00000080 - U-000007FF, mask 110XXXXX
 	                // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-	                $char = pack('C*', $ord_var_c, ord($val{$c + 1}));
+	                $char = pack('C*', $ord_var_c, ord($val[$c + 1]));
 	                $c += 1;
 	                $utf16 = utf82utf16($char);
 	                $ascii .= sprintf('\u%04s', bin2hex($utf16));
@@ -162,7 +162,7 @@ function _val($val)
 	            case (($ord_var_c & 0xF0) == 0xE0):
 	                // characters U-00000800 - U-0000FFFF, mask 1110XXXX
 	                // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-	                $char = pack('C*', $ord_var_c, ord($val{$c + 1}), ord($val{$c + 2}));
+	                $char = pack('C*', $ord_var_c, ord($val[$c + 1]), ord($val[$c + 2]));
 	                $c += 2;
 	                $utf16 = utf82utf16($char);
 	                $ascii .= sprintf('\u%04s', bin2hex($utf16));
@@ -171,7 +171,7 @@ function _val($val)
 	            case (($ord_var_c & 0xF8) == 0xF0):
 	                // characters U-00010000 - U-001FFFFF, mask 11110XXX
 	                // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-	                $char = pack('C*', $ord_var_c, ord($val{$c + 1}), ord($val{$c + 2}), ord($val{$c + 3}));
+	                $char = pack('C*', $ord_var_c, ord($val[$c + 1]), ord($val[$c + 2]), ord($val[$c + 3]));
 	                $c += 3;
 	                $utf16 = utf82utf16($char);
 	                $ascii .= sprintf('\u%04s', bin2hex($utf16));
@@ -180,7 +180,7 @@ function _val($val)
 	            case (($ord_var_c & 0xFC) == 0xF8):
 	                // characters U-00200000 - U-03FFFFFF, mask 111110XX
 	                // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-	                $char = pack('C*', $ord_var_c, ord($val{$c + 1}), ord($val{$c + 2}), ord($val{$c + 3}), ord($val{$c + 4}));
+	                $char = pack('C*', $ord_var_c, ord($val[$c + 1]), ord($val[$c + 2]), ord($val[$c + 3]), ord($val[$c + 4]));
 	                $c += 4;
 	                $utf16 = utf82utf16($char);
 	                $ascii .= sprintf('\u%04s', bin2hex($utf16));
@@ -189,7 +189,7 @@ function _val($val)
 	            case (($ord_var_c & 0xFE) == 0xFC):
 	                // characters U-04000000 - U-7FFFFFFF, mask 1111110X
 	                // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
-	                $char = pack('C*', $ord_var_c, ord($val{$c + 1}), ord($val{$c + 2}), ord($val{$c + 3}), ord($val{$c + 4}), ord($val{$c + 5}));
+	                $char = pack('C*', $ord_var_c, ord($val[$c + 1]), ord($val[$c + 2]), ord($val[$c + 3]), ord($val[$c + 4]), ord($val[$c + 5]));
 	                $c += 5;
 	                $utf16 = utf82utf16($char);
 	                $ascii .= sprintf('\u%04s', bin2hex($utf16));
diff --git a/htdocs/install/inc.php b/htdocs/install/inc.php
index 2e7099d84b8..c8dc7fd4382 100644
--- a/htdocs/install/inc.php
+++ b/htdocs/install/inc.php
@@ -258,9 +258,6 @@ $langs = new Translate('..', $conf);
 if (GETPOST('lang', 'aZ09')) $langs->setDefaultLang(GETPOST('lang', 'aZ09'));
 else $langs->setDefaultLang('auto');
 
-$bc[false]=' class="bg1"';
-$bc[true]=' class="bg2"';
-
 
 /**
  * Load conf file (file must exists)
diff --git a/test/phpunit/FunctionsLibTest.php b/test/phpunit/FunctionsLibTest.php
index 5b2b65c9e50..2a7734716eb 100644
--- a/test/phpunit/FunctionsLibTest.php
+++ b/test/phpunit/FunctionsLibTest.php
@@ -1260,4 +1260,25 @@ class FunctionsLibTest extends PHPUnit\Framework\TestCase
 
         return true;
     }
+
+    /**
+     * testDolStringIsGoodIso
+     *
+     * @return boolean
+     */
+    public function testDolStringIsGoodIso()
+    {
+    	global $conf, $langs;
+
+    	$chaine='This is an ISO string';
+    	$result = dol_string_is_good_iso($chaine);
+    	$this->assertEquals($result, 1);
+
+    	$chaine='This is a not ISO string '.chr(0);
+    	$result = dol_string_is_good_iso($chaine);
+    	$this->assertEquals($result, 0);
+
+    	return true;
+    }
+
 }