Adjust --no-clear option for repetitive relaunching

Related: https://gist.github.com/junegunn/4963bab6ace453f7f529d2d0e01b1d85

Close #974

src/tui/light.go

@@ -182,10 +182,18 @@ func (r *LightRenderer) Init() {
 	if r.fullscreen {
 		r.smcup()
 	} else {
-		r.csi("J")
+		// We assume that --no-clear is used for repetitive relaunching of fzf.
+		// So we do not clear the lower bottom of the screen.
+		if r.clearOnExit {
+			r.csi("J")
+		}
 		y, x := r.findOffset()
 		r.mouse = r.mouse && y >= 0
-		if x > 0 {
+		// When --no-clear is used for repetitive relaunching, there is a small
+		// time frame between fzf processes where the user keystrokes are not
+		// captured by either of fzf process which can cause x offset to be
+		// increased and we're left with unwanted extra new line.
+		if x > 0 && r.clearOnExit {
 			r.upOneLine = true
 			r.makeSpace()
 		}
@@ -200,7 +208,7 @@ func (r *LightRenderer) Init() {
 	r.csi(fmt.Sprintf("%dA", r.MaxY()-1))
 	r.csi("G")
 	r.csi("K")
-	// r.csi("s")
+	r.csi("s")
 	if !r.fullscreen && r.mouse {
 		r.yoffset, _ = r.findOffset()
 	}
@@ -586,10 +594,8 @@ func (r *LightRenderer) Close() {
 			}
 			r.csi("J")
 		}
-	} else if r.fullscreen {
-		r.csi("G")
-	} else {
-		r.move(r.height, 0)
+	} else if !r.fullscreen {
+		r.csi("u")
 	}
 	if r.mouse {
 		r.csi("?1000l")