Adjust --no-clear option for repetitive relaunching

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

Close #974

src/terminal.go

@@ -87,6 +87,7 @@ type Terminal struct {
 	margin     [4]sizeSpec
 	strong     tui.Attr
 	bordered   bool
+	cleanExit  bool
 	border     tui.Window
 	window     tui.Window
 	pborder    tui.Window
@@ -366,6 +367,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		history:    opts.History,
 		margin:     opts.Margin,
 		bordered:   opts.Bordered,
+		cleanExit:  opts.ClearOnExit,
 		strong:     strongAttr,
 		cycle:      opts.Cycle,
 		header:     header,
@@ -1341,7 +1343,14 @@ func (t *Terminal) Loop() {
 		}()
 	}
 
-	exit := func(code int) {
+	exit := func(code int, printQuery bool) {
+		if !t.cleanExit && t.fullscreen && t.inlineInfo {
+			t.placeCursor()
+		}
+		t.tui.Close()
+		if printQuery {
+			t.printer(string(t.input))
+		}
 		if code <= exitNoMatch && t.history != nil {
 			t.history.append(string(t.input))
 		}
@@ -1389,11 +1398,11 @@ func (t *Terminal) Loop() {
 					case reqRedraw:
 						t.redraw()
 					case reqClose:
-						t.tui.Close()
 						if t.output() {
-							exit(exitOk)
+							exit(exitOk, false)
+						} else {
+							exit(exitNoMatch, false)
 						}
-						exit(exitNoMatch)
 					case reqPreviewDisplay:
 						t.previewer.text = value.(string)
 						t.previewer.lines = strings.Count(t.previewer.text, "\n")
@@ -1402,12 +1411,9 @@ func (t *Terminal) Loop() {
 					case reqPreviewRefresh:
 						t.printPreview()
 					case reqPrintQuery:
-						t.tui.Close()
-						t.printer(string(t.input))
-						exit(exitOk)
+						exit(exitOk, true)
 					case reqQuit:
-						t.tui.Close()
-						exit(exitInterrupt)
+						exit(exitInterrupt, false)
 					}
 				}
 				t.placeCursor()

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")

test/test_go.rb

@@ -1253,11 +1253,12 @@ class TestGoFZF < TestBase
   end
 
   def test_no_clear
-    tmux.send_keys 'seq 100 | fzf --no-clear --inline-info --height 5', :Enter
-    prompt = '>   < 100/100'
+    tmux.send_keys "seq 10 | fzf --no-clear --inline-info --height 5 > #{tempname}", :Enter
+    prompt = '>   < 10/10'
     tmux.until { |lines| lines[-1] == prompt }
     tmux.send_keys :Enter
-    tmux.until { |lines| lines[-2] == prompt && lines[-1] == '1' }
+    tmux.until { |_| %w[1] == File.readlines(tempname).map(&:chomp) }
+    tmux.until { |lines| lines[-1] == prompt }
   end
 
   def test_change_top