Quick/Bulk Edit: Fix the Tag suggestions position on the Bulk Edit textarea.

Always passes the complete `position` object to the jQuery autocomplete widget.
Also checks if an autocomplete instance already exists on the Bulk Edit textarea.

Props davidbenton.
Fixes #40242.

Merges [40357] to the 4.7 branch.


git-svn-id: https://develop.svn.wordpress.org/branches/4.7@40365 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/js/inline-edit-post.js

@@ -115,6 +115,15 @@ inlineEditPost = {
 		// enable autocomplete for tags
 		if ( 'post' === type ) {
 			$( 'tr.inline-editor textarea[data-wp-taxonomy]' ).each( function ( i, element ) {
+				/*
+				 * While Quick Edit clones the form each time, Bulk Edit always re-uses
+				 * the same form. Let's check if an autocomplete instance already exists.
+				 */
+				if ( $( element ).autocomplete( 'instance' ) ) {
+					// jQuery equivalent of `continue` within an `each()` loop.
+					return;
+				}
+
 				$( element ).wpTagsSuggest();
 			} );
 		}

src/wp-admin/js/tags-suggest.js

@@ -120,7 +120,9 @@
 			},
 			minLength: 2,
 			position: {
-				my: 'left top+2'
+				my: 'left top+2',
+				at: 'left bottom',
+				collision: 'none'
 			},
 			messages: {
 				noResults: window.uiAutocompleteL10n.noResults,