Don't use tcell's Rune() for non-KeyRune events

According to tcell documentation, Rune() should only be used for KeyRune
events. Otherwise its return value is not guaranteed and should not be
relied upon.

This fixes issue zyedidia#2947: Esc key not working on Windows, since tcell
sends lone Esc key event with rune == 0 on Unix but with rune == 27
(the keycode) on Windows.

Author: dmaluka

internal/action/bindings.go

@@ -176,31 +176,18 @@ modSearch:
 		// see if the key is in bindingKeys with the Ctrl prefix.
 		k = string(unicode.ToUpper(rune(k[0]))) + k[1:]
 		if code, ok := keyEvents["Ctrl"+k]; ok {
-			var r tcell.Key
-			// Special case for escape, for some reason tcell doesn't send it with the esc character
-			if code < 256 && code != 27 {
-				r = code
-			}
-			// It is, we're done.
 			return KeyEvent{
 				code: code,
 				mod:  modifiers,
-				r:    rune(r),
 			}, true
 		}
 	}
 
 	// See if we can find the key in bindingKeys
 	if code, ok := keyEvents[k]; ok {
-		var r tcell.Key
-		// Special case for escape, for some reason tcell doesn't send it with the esc character
-		if code < 256 && code != 27 {
-			r = code
-		}
 		return KeyEvent{
 			code: code,
 			mod:  modifiers,
-			r:    rune(r),
 		}, true
 	}
 

internal/action/bufpane.go

@@ -472,7 +472,9 @@ func (h *BufPane) HandleEvent(event tcell.Event) {
 		ke := KeyEvent{
 			code: e.Key(),
 			mod:  metaToAlt(e.Modifiers()),
-			r:    e.Rune(),
+		}
+		if e.Key() == tcell.KeyRune {
+			ke.r = e.Rune()
 		}
 
 		done := h.DoKeyEvent(ke)

internal/action/events.go

@@ -68,7 +68,7 @@ func (k KeyEvent) Name() string {
 		if k.code == tcell.KeyRune {
 			s = string(k.r)
 		} else {
-			s = fmt.Sprintf("Key[%d,%d]", k.code, int(k.r))
+			s = fmt.Sprintf("Key[%d]", k.code)
 		}
 	}
 	if len(m) != 0 {
@@ -155,11 +155,14 @@ func (m MouseEvent) Name() string {
 func ConstructEvent(event tcell.Event) (Event, error) {
 	switch e := event.(type) {
 	case *tcell.EventKey:
-		return KeyEvent{
+		ke := KeyEvent{
 			code: e.Key(),
 			mod:  metaToAlt(e.Modifiers()),
-			r:    e.Rune(),
-		}, nil
+		}
+		if e.Key() == tcell.KeyRune {
+			ke.r = e.Rune()
+		}
+		return ke, nil
 	case *tcell.EventRaw:
 		return RawEvent{
 			esc: e.EscSeq(),

internal/action/infopane.go

@@ -89,7 +89,9 @@ func (h *InfoPane) HandleEvent(event tcell.Event) {
 		ke := KeyEvent{
 			code: e.Key(),
 			mod:  metaToAlt(e.Modifiers()),
-			r:    e.Rune(),
+		}
+		if e.Key() == tcell.KeyRune {
+			ke.r = e.Rune()
 		}
 
 		done := h.DoKeyEvent(ke)

internal/action/termpane.go

@@ -128,7 +128,9 @@ func (t *TermPane) HandleEvent(event tcell.Event) {
 		ke := KeyEvent{
 			code: e.Key(),
 			mod:  metaToAlt(e.Modifiers()),
-			r:    e.Rune(),
+		}
+		if e.Key() == tcell.KeyRune {
+			ke.r = e.Rune()
 		}
 		action, more := TermBindings.NextEvent(ke, nil)