diff --git a/htdocs/core/class/extrafields.class.php b/htdocs/core/class/extrafields.class.php
index ca703979a7d..2ca0bf6b439 100644
--- a/htdocs/core/class/extrafields.class.php
+++ b/htdocs/core/class/extrafields.class.php
@@ -1597,7 +1597,7 @@ class ExtraFields
 		if (!empty($extrafieldsobjectkey)) {
 			$label = $this->attributes[$extrafieldsobjectkey]['label'][$key];
 			$type = $this->attributes[$extrafieldsobjectkey]['type'][$key];
-			$size = $this->attributes[$extrafieldsobjectkey]['size'][$key];
+			$size = (int) $this->attributes[$extrafieldsobjectkey]['size'][$key];
 			$default = $this->attributes[$extrafieldsobjectkey]['default'][$key];
 			$computed = $this->attributes[$extrafieldsobjectkey]['computed'][$key];
 			$unique = $this->attributes[$extrafieldsobjectkey]['unique'][$key];
@@ -1666,7 +1666,7 @@ class ExtraFields
 				$value = price($value, 0, $langs, 0, 0, -1);
 			}
 		} elseif ($type == 'select') {
-			$valstr = $param['options'][$value];
+			$valstr = (!empty($param['options'][$value]) ? $param['options'][$value] : '');
 			if (($pos = strpos($valstr, "|")) !== false) {
 				$valstr = substr($valstr, 0, $pos);
 			}
diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 8b0b482f33f..b18ed68eaa2 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -6684,7 +6684,7 @@ class Form
 				if (!dol_eval($val['enabled'], 1, 1)) {
 					continue;
 				}
-				if ($val['showoncombobox']) {
+				if (!empty($val['showoncombobox'])) {
 					$tmpfieldstoshow .= ($tmpfieldstoshow ? ',' : '').'t.'.$key;
 				}
 			}
@@ -6817,7 +6817,7 @@ class Form
 
 			if (!$forcecombo) {
 				include_once DOL_DOCUMENT_ROOT.'/core/lib/ajax.lib.php';
-				$out .= ajax_combobox($htmlname, null, $conf->global->$confkeyforautocompletemode);
+				$out .= ajax_combobox($htmlname, null, (!empty($conf->global->$confkeyforautocompletemode) ? $conf->global->$confkeyforautocompletemode : 0));
 			}
 		} else {
 			dol_print_error($this->db);
diff --git a/htdocs/core/tpl/extrafields_list_print_fields.tpl.php b/htdocs/core/tpl/extrafields_list_print_fields.tpl.php
index 5ea0e4821d6..4c56b0223cd 100644
--- a/htdocs/core/tpl/extrafields_list_print_fields.tpl.php
+++ b/htdocs/core/tpl/extrafields_list_print_fields.tpl.php
@@ -35,7 +35,7 @@ if (!empty($extrafieldsobjectkey)) {	// $extrafieldsobject is the $object->table
 					}
 					$value = $datenotinstring;
 				} else {
-					$value = $obj->$tmpkey;
+					$value = (!empty($obj->$tmpkey) ? $obj->$tmpkey : '');
 				}
 				// If field is a computed field, we make computation to get value
 				if ($extrafields->attributes[$extrafieldsobjectkey]['computed'][$key]) {
diff --git a/htdocs/core/tpl/extrafields_list_search_input.tpl.php b/htdocs/core/tpl/extrafields_list_search_input.tpl.php
index 77329eb06a4..72f888f256a 100644
--- a/htdocs/core/tpl/extrafields_list_search_input.tpl.php
+++ b/htdocs/core/tpl/extrafields_list_search_input.tpl.php
@@ -37,17 +37,17 @@ if (!empty($extrafieldsobjectkey)) {	// $extrafieldsobject is the $object->table
 					if (in_array($typeofextrafield, array('int', 'double'))) {
 						$searchclass = 'searchnum';
 					}
-					print '<input class="flat'.($searchclass ? ' '.$searchclass : '').'" size="4" type="text" name="'.$search_options_pattern.$tmpkey.'" value="'.dol_escape_htmltag($search_array_options[$search_options_pattern.$tmpkey]).'">';
+					print '<input class="flat'.($searchclass ? ' '.$searchclass : '').'" size="4" type="text" name="'.$search_options_pattern.$tmpkey.'" value="'.dol_escape_htmltag((empty($search_array_options[$search_options_pattern.$tmpkey]) ? '' : $search_array_options[$search_options_pattern.$tmpkey])).'">';
 				} elseif (in_array($typeofextrafield, array('datetime', 'timestamp'))) {
 					$morecss = '';
-					echo $extrafields->showInputField($key, $search_array_options[$search_options_pattern.$tmpkey], '', '', $search_options_pattern, $morecss, 0, $extrafieldsobjectkey, 1);
+					echo $extrafields->showInputField($key, (empty($search_array_options[$search_options_pattern.$tmpkey]) ? '' : $search_array_options[$search_options_pattern.$tmpkey]), '', '', $search_options_pattern, $morecss, 0, $extrafieldsobjectkey, 1);
 				} else {
 					// for the type as 'checkbox', 'chkbxlst', 'sellist' we should use code instead of id (example: I declare a 'chkbxlst' to have a link with dictionnairy, I have to extend it with the 'code' instead 'rowid')
 					$morecss = '';
 					if (in_array($typeofextrafield, array('link', 'sellist', 'text', 'html'))) {
 						$morecss = 'maxwidth200';
 					}
-					echo $extrafields->showInputField($key, $search_array_options[$search_options_pattern.$tmpkey], '', '', $search_options_pattern, $morecss, 0, $extrafieldsobjectkey, 1);
+					echo $extrafields->showInputField($key, (empty($search_array_options[$search_options_pattern.$tmpkey]) ? '' : $search_array_options[$search_options_pattern.$tmpkey]), '', '', $search_options_pattern, $morecss, 0, $extrafieldsobjectkey, 1);
 				}
 				print '</td>';
 			}