fix rstudio/pagedown#329: provide a fallback favicon.ico

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: servr
 Type: Package
 Title: A Simple HTTP Server to Serve Static Files or Dynamic Documents
-Version: 0.30.1
+Version: 0.30.2
 Authors@R: c(
   person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
   person("Carson", "Sievert", role = "ctb"),
@@ -31,4 +31,4 @@ License: GPL
 URL: https://github.com/yihui/servr
 BugReports: https://github.com/yihui/servr/issues
 Encoding: UTF-8
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2

NEWS.md

@@ -1,5 +1,6 @@
 # CHANGES IN servr VERSION 0.31
 
+- A fallback `favicon.ico` will be provided if it does not exist when serving files (thanks, @MMJansen, rstudio/pagedown#329).
 
 # CHANGES IN servr VERSION 0.30
 

R/static.R

@@ -325,7 +325,10 @@ serve_dir = function(dir = '.', response = NULL) function(req) {
     # because it will be treated as /foo/bar/404.html; if 404.html contains
     # paths like ./css/style.css, I don't know how to let the browser know that
     # it means /css/style.css instead of /foo/bar/css/style.css
-    if (!file.exists(path)) return(if (try_404(path)) list(
+    if (!file.exists(path)) return(if (path == './favicon.ico') list(
+      status = 200L, body = xfun::read_bin(file.path(R.home('doc'), 'html', 'favicon.ico')),
+      headers = list('Content-Type' = 'image/x-icon')
+    ) else if (try_404(path)) list(
       status = 302L, body = '', headers = list('Location' = '/404.html')
     ) else list(
       status = 404L, headers = list('Content-Type' = 'text/plain'),