Improve Content-Range logic to support video streaming better (#198)

* Improve `Content-Range` logic to support

* require start range for simpler code

Author: fonsp

src/server.jl

@@ -461,19 +461,23 @@ function serve_file(
         end
     end
 
-    range_match = match(r"bytes=(\d+)-(\d+)" , HTTP.header(req, "Range", ""))
+    range_match = match(r"^bytes=(\d+)-(\d*)$" , HTTP.header(req, "Range", ""))
     is_ranged = !isnothing(range_match)
 
     headers = [
         "Content-Type" => content_type,
     ]
     if is_ranged
-        range = parse.(Int, range_match.captures)
+        p(s) = isempty(s) ? nothing : parse(Int64, s)
+        start, stop = p.(range_match.captures)
+        @assert start isa Int64 # because the regex requires at least one digit
+        stop = something(stop, binary_length(content) - 1)
+    
         push!(headers,
             "Content-Range" =>
-            "bytes $(range[1])-$(range[2])/$(binary_length(content))"
+            "bytes $(start)-$(stop)/$(binary_length(content))"
         )
-        content  = @view content[1+range[1]:1+range[2]]
+        content  = @view content[1+start:1+stop]
         ret_code = 206
     end
     if allow_cors