Fixes for Cygwin

- Update install script to download Windows binary if $TERM == cygwin
- Unset TERM if $TERM == cygwin (#933)
- Always use cmd.exe instead of $SHELL when running commands

src/tui/tcell.go

@@ -3,6 +3,7 @@
 package tui
 
 import (
+	"os"
 	"time"
 	"unicode/utf8"
 
@@ -140,6 +141,9 @@ func (r *FullscreenRenderer) initScreen() {
 }
 
 func (r *FullscreenRenderer) Init() {
+	if os.Getenv("TERM") == "cygwin" {
+		os.Setenv("TERM", "")
+	}
 	encoding.Register()
 
 	r.initScreen()

src/util/util_windows.go

@@ -12,15 +12,11 @@ import (
 
 // ExecCommand executes the given command with $SHELL
 func ExecCommand(command string) *exec.Cmd {
-	shell := os.Getenv("SHELL")
-	if len(shell) == 0 {
-		shell = "cmd"
-	}
 	args, _ := shellwords.Parse(command)
 	allArgs := make([]string, len(args)+1)
 	allArgs[0] = "/c"
 	copy(allArgs[1:], args)
-	return exec.Command(shell, allArgs...)
+	return exec.Command("cmd", allArgs...)
 }
 
 // IsWindows returns true on Windows