Skip hidden files when counting visible files in list (#26522)

The file list UI logic that renders the next page doesn't properly
exclude hidden files when not shown. This fix makes sure that only rows
that are actually visible are counted when rendering a page, this makes
sure that the page will always have enough elements displayed.

apps/files/js/filelist.js

@@ -923,7 +923,8 @@
 				tr,
 				fileData,
 				newTrs = [],
-				isAllSelected = this.isAllSelected();
+				isAllSelected = this.isAllSelected(),
+				showHidden = this._filesConfig.get('showhidden');
 
 			if (index >= this.files.length) {
 				return false;
@@ -947,7 +948,10 @@
 				}
 				newTrs.push(tr);
 				index++;
-				count--;
+				// only count visible rows
+				if (showHidden || !tr.hasClass('hidden-file')) {
+					count--;
+				}
 			}
 
 			// trigger event for newly added rows

apps/files/tests/js/filelistSpec.js

@@ -1120,6 +1120,34 @@ describe('OCA.Files.FileList tests', function() {
 			expect(fileList.files.length).toEqual(65);
 			expect($('#fileList tr').length).toEqual(20);
 		});
+		it('renders the full first page despite hidden rows', function() {
+			filesConfig.set('showhidden', false);
+			var files = _.map(generateFiles(0, 23), function(data) {
+				return _.extend(data, {
+					name: '.' + data.name
+				});
+			});
+			// only hidden files + one visible
+			files.push(testFiles[0]);
+			fileList.setFiles(files);
+			expect(fileList.files.length).toEqual(25);
+			// render 24 hidden elements + the visible one
+			expect($('#fileList tr').length).toEqual(25);
+		});
+		it('renders the full first page despite hidden rows', function() {
+			filesConfig.set('showhidden', true);
+			var files = _.map(generateFiles(0, 23), function(data) {
+				return _.extend(data, {
+					name: '.' + data.name
+				});
+			});
+			// only hidden files + one visible
+			files.push(testFiles[0]);
+			fileList.setFiles(files);
+			expect(fileList.files.length).toEqual(25);
+			// render 20 first hidden elements as visible
+			expect($('#fileList tr').length).toEqual(20);
+		});
 		it('renders the second page when scrolling down (trigger nextPage)', function() {
 			// TODO: can't simulate scrolling here, so calling nextPage directly
 			fileList._nextPage(true);