Fix short Firefox cell height for dropdown cells

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 - [#670](https://github.com/plotly/dash-table/pull/670) Fix a bug where `derived_filter_query_structure` was not getting updated properly
+- [#665](https://github.com/plotly/dash-table/pull/665) Fix a bug in Firefox where the dropdown cells height is incorrect
 
 ## [4.5.1] - 2019-11-14
 ### Fixed

src/dash-table/components/Table/Table.less

@@ -399,6 +399,18 @@
 		}
             }
 
+        /*
+         * fixes Firefox td height bug on td > dropdown children
+         * bug should only appear on FF but
+         * @supports = scoped to Firefox only
+         * to minimize side effects
+         */
+        @supports (-moz-appearance:none) {
+            td.dropdown .dash-cell-value-container {
+                height: auto;
+            }
+        }
+
             th.dash-filter {
 		position: relative;