improve compatibility with Tmux

This fixes: #19

Author: ALizarazoTellez

graphic/display.go

@@ -115,6 +115,13 @@ func (d *Display) Init(sampleRate float64, sampleSize int) error {
 
 	d.styleBuffer = make([]termbox.Attribute, 4096)
 
+	// Prevent crash on Tmux.
+	prevState, err := normalizeTerminal()
+	if err != nil {
+		return err
+	}
+	defer prevState()
+
 	if err := termbox.Init(); err != nil {
 		return err
 	}

graphic/terminal.go

@@ -0,0 +1,31 @@
+package graphic
+
+import (
+	"os"
+	"strings"
+)
+
+// normalizeTerminal looks for incompatibilities in the terminal configuration
+// with the underlying rendering libraries (Termbox) and makes some adjustments
+// to avoid problems.
+//
+// Returns a function that allows you to restore the terminal configuration to its original state.
+func normalizeTerminal() (func(), error) {
+	prevTERMINFO := os.Getenv("TERMINFO")
+
+	if strings.HasPrefix(os.Getenv("TERM"), "tmux") {
+		// Some combinations of TERMINFO with TERM in some Tmux value
+		// will cause Termbox to fail.
+		if err := os.Unsetenv("TERMINFO"); err != nil {
+			return nil, err
+		}
+	}
+
+	restore := func() {
+		if err := os.Setenv("TERMINFO", prevTERMINFO); err != nil {
+			panic(err)
+		}
+	}
+
+	return restore, nil
+}