Remove invalid 'result' event when using --sync option

When the search for the initial query doesn't finish immediately
fzf would trigger an invalid 'result' event for an empty query.

  seq 100 | fzf --query 99 --bind result:accept --sync
    # Prints 99

  seq 1000000 | fzf --query 99 --bind result:accept --sync
    # Should print 99, but fzf would print 1

man/man1/fzf.1

@@ -812,7 +812,7 @@ e.g.
 .TP
 .B "--sync"
 Synchronous search for multi-staged filtering. If specified, fzf will launch
-ncurses finder only after the input stream is complete.
+the finder only after the input stream is complete.
 
 .RS
 e.g. \fBfzf --multi | fzf --sync\fR

src/core.go

@@ -298,8 +298,7 @@ func Run(opts *Options, version string, revision string) {
 					total = count
 					terminal.UpdateCount(total, !reading, value.(*string))
 					if opts.Sync {
-						opts.Sync = false
-						terminal.UpdateList(PassMerger(&snapshot, opts.Tac, snapshotRevision))
+						terminal.UpdateList(PassMerger(&snapshot, opts.Tac, snapshotRevision), false)
 					}
 					if heightUnknown && !deferred {
 						determine(!reading)
@@ -384,7 +383,7 @@ func Run(opts *Options, version string, revision string) {
 								determine(val.final)
 							}
 						}
-						terminal.UpdateList(val)
+						terminal.UpdateList(val, true)
 					}
 				}
 			}

src/terminal.go

@@ -1067,7 +1067,7 @@ func (t *Terminal) UpdateProgress(progress float32) {
 }
 
 // UpdateList updates Merger to display the list
-func (t *Terminal) UpdateList(merger *Merger) {
+func (t *Terminal) UpdateList(merger *Merger, triggerResultEvent bool) {
 	t.mutex.Lock()
 	prevIndex := minItem.Index()
 	reset := t.revision != merger.Revision()
@@ -1118,7 +1118,7 @@ func (t *Terminal) UpdateList(merger *Merger) {
 				t.eventChan <- one
 			}
 		}
-		if t.hasResultActions {
+		if triggerResultEvent && t.hasResultActions {
 			t.eventChan <- tui.Result.AsEvent()
 		}
 	}