Fix querying device attributes on Windows (#31)

Author: jwortmann

src/Sixel.jl

@@ -46,7 +46,8 @@ Check if given terminal `tty` supports sixel format.
     (Experiment) The return value is not fully tested on all terminals and all platforms.
 """
 function is_sixel_supported(tty::Base.TTY=stdout)
-    '4' in TerminalTools.query_terminal("\033[0c", tty)
+    device_attributes = TerminalTools.query_terminal("\033[0c", tty)
+    "4" in split(chop(device_attributes), ';')
 end
 is_sixel_supported(io::IO) = false
 

src/terminaltools.jl

@@ -54,7 +54,15 @@ function query_terminal(msg, tty::TTY; timeout=1)
         timeout_call(timeout; pollint=timeout/100) do
             with_raw(term) do
                 write(tty, msg)
-                return transcode(String, readavailable(tty))
+                return @static if Sys.iswindows()
+                    response = ""
+                    while !endswith(response, 'c')
+                        response *= read(stdin, Char)
+                    end
+                    response
+                else
+                    transcode(String, readavailable(tty))
+                end
             end
         end
     catch e