Fix non-working raw escape bindings after restarting the screen (zyedidia#3468)

When we temporarily disable the screen (e.g. during RunInteractiveShell)
and then enable it again, we reinitialize tcell.Screen from scratch, so
we need to register all previously registered raw escape sequences once
again. Otherwise raw escape bindings stop working, since the list of
raw escape sequences of this newly create tcell.Screen is empty.

Fixes zyedidia#3392

Author: dmaluka

internal/action/bindings.go

@@ -89,7 +89,7 @@ func BindKey(k, v string, bind func(e Event, a string)) {
 	}
 
 	if strings.HasPrefix(k, "\x1b") {
-		screen.Screen.RegisterRawSeq(k)
+		screen.RegisterRawSeq(k)
 	}
 
 	bind(event, v)
@@ -342,7 +342,7 @@ func UnbindKey(k string) error {
 		}
 
 		if strings.HasPrefix(k, "\x1b") {
-			screen.Screen.UnregisterRawSeq(k)
+			screen.UnregisterRawSeq(k)
 		}
 
 		defaults := DefaultBindings("buffer")

internal/screen/screen.go

@@ -33,6 +33,12 @@ var lock sync.Mutex
 // written to even if no event user event has occurred
 var drawChan chan bool
 
+// rawSeq is the list of raw escape sequences that are bound to some actions
+// via keybindings and thus should be parsed by tcell. We need to register
+// them in tcell every time we reinitialize the screen, so we need to remember
+// them in a list
+var rawSeq = make([]string, 0)
+
 // Lock locks the screen lock
 func Lock() {
 	lock.Lock()
@@ -121,6 +127,34 @@ func SetContent(x, y int, mainc rune, combc []rune, style tcell.Style) {
 	}
 }
 
+// RegisterRawSeq registers a raw escape sequence that should be parsed by tcell
+func RegisterRawSeq(r string) {
+	for _, seq := range rawSeq {
+		if seq == r {
+			return
+		}
+	}
+	rawSeq = append(rawSeq, r)
+
+	if Screen != nil {
+		Screen.RegisterRawSeq(r)
+	}
+}
+
+// UnregisterRawSeq unregisters a raw escape sequence that should be parsed by tcell
+func UnregisterRawSeq(r string) {
+	for i, seq := range rawSeq {
+		if seq == r {
+			rawSeq[i] = rawSeq[len(rawSeq)-1]
+			rawSeq = rawSeq[:len(rawSeq)-1]
+		}
+	}
+
+	if Screen != nil {
+		Screen.UnregisterRawSeq(r)
+	}
+}
+
 // TempFini shuts the screen down temporarily
 func TempFini() bool {
 	screenWasNil := Screen == nil
@@ -195,6 +229,10 @@ func Init() error {
 		Screen.EnableMouse()
 	}
 
+	for _, r := range rawSeq {
+		Screen.RegisterRawSeq(r)
+	}
+
 	return nil
 }