Fix file picker not respecting hidden files settings

This will only respect the setting inside the file app. For other apps
we will either need to do an API call or add an input field with the
same idea to spare a blocking api call.

Signed-off-by: Carl Schwan <carl@carlschwan.eu>

core/src/OC/dialogs.js

@@ -1143,6 +1143,16 @@ const Dialogs = {
 				})
 			}
 
+			// Check if the showHidden input field exist and if it exist follow it
+			// Otherwise just show the hidden files
+			const showHiddenInput = document.getElementById('showHiddenFiles')
+			const showHidden = showHiddenInput === null || showHiddenInput.value === "1"
+			if (!showHidden) {
+				files = files.filter(function(file) {
+					return !file.name.startsWith('.')
+				})
+			}
+
 			var Comparators = {
 				name: function(fileInfo1, fileInfo2) {
 					if (fileInfo1.type === 'dir' && fileInfo2.type !== 'dir') {