fix(dropdown): paste values as search query

Pasting inside a search dropdown was fetched to automatically select items in 2.9.0
Unfortunately if items are not found the paste value is completely lost. Especially remote call were not possible anymore.

This PR leaves the pasted text in case no items are found and put it into the search input again

Author: lubber-de

src/definitions/modules/dropdown.js

@@ -1080,12 +1080,28 @@
                     paste: function (event) {
                         var
                             pasteValue = (event.originalEvent.clipboardData || window.clipboardData).getData('text'),
-                            tokens = pasteValue.split(settings.delimiter)
+                            tokens = pasteValue.split(settings.delimiter),
+                            notFoundTokens = []
                         ;
                         tokens.forEach(function (value) {
-                            module.set.selected(module.escape.htmlEntities(value.trim()), null, true, true);
+                            if (module.set.selected(module.escape.htmlEntities(value.trim()), null, true, true) === false) {
+                                notFoundTokens.push(value);
+                            }
                         });
                         event.preventDefault();
+                        if (notFoundTokens.length > 0) {
+                            var searchEl = $search[0],
+                                startPos = searchEl.selectionStart,
+                                endPos = searchEl.selectionEnd,
+                                orgText = searchEl.value,
+                                pasteText = notFoundTokens.join(settings.delimiter),
+                                newEndPos = startPos + pasteText.length
+                            ;
+                            $search.val(orgText.slice(0, startPos) + pasteText + orgText.slice(endPos));
+                            searchEl.selectionStart = newEndPos;
+                            searchEl.selectionEnd = newEndPos;
+                            module.event.input(event);
+                        }
                     },
                     change: function () {
                         if (!internalChange) {
@@ -2726,7 +2742,7 @@
                             ? $selectedItem || module.get.itemWithAdditions(value)
                             : $selectedItem || module.get.item(value);
                         if (!$selectedItem) {
-                            return;
+                            return false;
                         }
                         module.debug('Setting selected menu item to', $selectedItem);
                         if (module.is.multiple()) {