Fixing favicon bug

Author: HammadTheOne

CHANGELOG.md

@@ -6,6 +6,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 - Unify the core Dash packages (dash, dashCoreComponents, dashHtmlComponents, dashTable) for streamlined maintenance and accessibility. The namespaces of these packages will be combined under the `dash` namespace, and all artifacts from the ancillary dash packages will be included with Dash for R. [#243](https://github.com/plotly/dashr/pull/243)
 
+### Fixed
+- Minor fix for favicon issue continued from [#240](https://github.com/plotly/dashr/pull/240) (for more details, see [#243](https://github.com/plotly/dashR/pull/243#issuecomment-842813526)).
+
 ## [0.9.1] - 2020-11-16
 ### Fixed
 - A regression which prevented favicons from displaying properly has been resolved, and a default Dash favicon is now supplied when none is provided in the `assets` directory. [#240](https://github.com/plotly/dashr/pull/240)

R/dash.R

@@ -500,8 +500,8 @@ Dash <- R6::R6Class(
                                      "/favicon.ico")
 
         # If custom favicon is not present, get the path for the default Dash favicon
-        if (is.na(names(asset_path))) {
-          asset_path <- system.file("extdata", "favicon.ico", package = "dash")
+        if (is.na(names(asset_path)) || is.null(asset_path)) {
+          asset_path <- setNames(system.file("extdata", "favicon.ico", package = "dash"), c("/favicon.ico"))
         }
 
         file_handle <- file(asset_path, "rb")