Fix bug where preview is not updated after reload when --disabled is set

Fix #3311

6 files changed, 81 insertions, 58 deletions

diff --git a/src/core.go b/src/core.go
index e049fb43..e21e8c0a 100644
--- a/src/core.go
+++ b/src/core.go
@@ -138,7 +138,9 @@ func Run(opts *Options, version string, revision string) {
 			opts.Fuzzy, opts.FuzzyAlgo, opts.Extended, opts.Case, opts.Normalize, forward, withPos,
 			opts.Filter == nil, opts.Nth, opts.Delimiter, runes)
 	}
-	matcher := NewMatcher(patternBuilder, sort, opts.Tac, eventBox)
+	inputRevision := 0
+	snapshotRevision := 0
+	matcher := NewMatcher(patternBuilder, sort, opts.Tac, eventBox, inputRevision)
 
 	// Filtering mode
 	if opts.Filter != nil {
@@ -209,8 +211,6 @@ func Run(opts *Options, version string, revision string) {
 
 	// Event coordination
 	reading := true
-	clearCache := util.Once(false)
-	clearSelection := util.Once(false)
 	ticks := 0
 	var nextCommand *string
 	eventBox.Watch(EvtReadNew)
@@ -234,17 +234,17 @@ func Run(opts *Options, version string, revision string) {
 	var count int
 	restart := func(command string) {
 		reading = true
-		clearCache = util.Once(true)
-		clearSelection = util.Once(true)
 		chunkList.Clear()
 		itemIndex = 0
+		inputRevision++
 		header = make([]string, 0, opts.HeaderLines)
 		go reader.restart(command)
 	}
 	for {
 		delay := true
 		ticks++
-		input := func(reloaded bool) []rune {
+		input := func() []rune {
+			reloaded := snapshotRevision != inputRevision
 			paused, input := terminal.Input()
 			if reloaded && paused {
 				query = []rune{}
@@ -277,18 +277,18 @@ func Run(opts *Options, version string, revision string) {
 					}
 					if !useSnapshot {
 						snapshot, count = chunkList.Snapshot()
+						snapshotRevision = inputRevision
 					}
 					total = count
 					terminal.UpdateCount(total, !reading, value.(*string))
 					if opts.Sync {
 						opts.Sync = false
-						terminal.UpdateList(PassMerger(&snapshot, opts.Tac), false)
+						terminal.UpdateList(PassMerger(&snapshot, opts.Tac, snapshotRevision))
 					}
 					if heightUnknown && !deferred {
 						determine(!reading)
 					}
-					reset := !useSnapshot && clearCache()
-					matcher.Reset(snapshot, input(reset), false, !reading, sort, reset)
+					matcher.Reset(snapshot, input(), false, !reading, sort, snapshotRevision)
 
 				case EvtSearchNew:
 					var command *string
@@ -313,17 +313,16 @@ func Run(opts *Options, version string, revision string) {
 					if !changed {
 						break
 					}
-					reset := false
 					if !useSnapshot {
 						newSnapshot, _ := chunkList.Snapshot()
 						// We want to avoid showing empty list when reload is triggered
 						// and the query string is changed at the same time i.e. command != nil && changed
 						if command == nil || len(newSnapshot) > 0 {
 							snapshot = newSnapshot
-							reset = clearCache()
+							snapshotRevision = inputRevision
 						}
 					}
-					matcher.Reset(snapshot, input(reset), true, !reading, sort, reset)
+					matcher.Reset(snapshot, input(), true, !reading, sort, snapshotRevision)
 					delay = false
 
 				case EvtSearchProgress:
@@ -363,7 +362,7 @@ func Run(opts *Options, version string, revision string) {
 								determine(val.final)
 							}
 						}
-						terminal.UpdateList(val, clearSelection())
+						terminal.UpdateList(val)
 					}
 				}
 			}
diff --git a/src/matcher.go b/src/matcher.go
index 22aa819c..b9288bb6 100644
--- a/src/matcher.go
+++ b/src/matcher.go
@@ -12,11 +12,11 @@ import (
 
 // MatchRequest represents a search request
 type MatchRequest struct {
-	chunks     []*Chunk
-	pattern    *Pattern
-	final      bool
-	sort       bool
-	clearCache bool
+	chunks   []*Chunk
+	pattern  *Pattern
+	final    bool
+	sort     bool
+	revision int
 }
 
 // Matcher is responsible for performing search
@@ -29,6 +29,7 @@ type Matcher struct {
 	partitions     int
 	slab           []*util.Slab
 	mergerCache    map[string]*Merger
+	revision       int
 }
 
 const (
@@ -38,7 +39,7 @@ const (
 
 // NewMatcher returns a new Matcher
 func NewMatcher(patternBuilder func([]rune) *Pattern,
-	sort bool, tac bool, eventBox *util.EventBox) *Matcher {
+	sort bool, tac bool, eventBox *util.EventBox, revision int) *Matcher {
 	partitions := util.Min(numPartitionsMultiplier*runtime.NumCPU(), maxPartitions)
 	return &Matcher{
 		patternBuilder: patternBuilder,
@@ -48,7 +49,8 @@ func NewMatcher(patternBuilder func([]rune) *Pattern,
 		reqBox:         util.NewEventBox(),
 		partitions:     partitions,
 		slab:           make([]*util.Slab, partitions),
-		mergerCache:    make(map[string]*Merger)}
+		mergerCache:    make(map[string]*Merger),
+		revision:       revision}
 }
 
 // Loop puts Matcher in action
@@ -70,8 +72,9 @@ func (m *Matcher) Loop() {
 			events.Clear()
 		})
 
-		if request.sort != m.sort || request.clearCache {
+		if request.sort != m.sort || request.revision != m.revision {
 			m.sort = request.sort
+			m.revision = request.revision
 			m.mergerCache = make(map[string]*Merger)
 			clearChunkCache()
 		}
@@ -140,11 +143,11 @@ func (m *Matcher) scan(request MatchRequest) (*Merger, bool) {
 
 	numChunks := len(request.chunks)
 	if numChunks == 0 {
-		return EmptyMerger, false
+		return EmptyMerger(request.revision), false
 	}
 	pattern := request.pattern
 	if pattern.IsEmpty() {
-		return PassMerger(&request.chunks, m.tac), false
+		return PassMerger(&request.chunks, m.tac, request.revision), false
 	}
 
 	cancelled := util.NewAtomicBool(false)
@@ -218,11 +221,11 @@ func (m *Matcher) scan(request MatchRequest) (*Merger, bool) {
 		partialResult := <-resultChan
 		partialResults[partialResult.index] = partialResult.matches
 	}
-	return NewMerger(pattern, partialResults, m.sort, m.tac), false
+	return NewMerger(pattern, partialResults, m.sort, m.tac, request.revision), false
 }
 
 // Reset is called to interrupt/signal the ongoing search
-func (m *Matcher) Reset(chunks []*Chunk, patternRunes []rune, cancel bool, final bool, sort bool, clearCache bool) {
+func (m *Matcher) Reset(chunks []*Chunk, patternRunes []rune, cancel bool, final bool, sort bool, revision int) {
 	pattern := m.patternBuilder(patternRunes)
 
 	var event util.EventType
@@ -231,5 +234,5 @@ func (m *Matcher) Reset(chunks []*Chunk, patternRunes []rune, cancel bool, final
 	} else {
 		event = reqRetry
 	}
-	m.reqBox.Set(event, MatchRequest{chunks, pattern, final, sort && pattern.sortable, clearCache})
+	m.reqBox.Set(event, MatchRequest{chunks, pattern, final, sort && pattern.sortable, revision})
 }
diff --git a/src/merger.go b/src/merger.go
index 5c12575c..6a235043 100644
--- a/src/merger.go
+++ b/src/merger.go
@@ -3,32 +3,36 @@ package fzf
 import "fmt"
 
 // EmptyMerger is a Merger with no data
-var EmptyMerger = NewMerger(nil, [][]Result{}, false, false)
+func EmptyMerger(revision int) *Merger {
+	return NewMerger(nil, [][]Result{}, false, false, revision)
+}
 
 // Merger holds a set of locally sorted lists of items and provides the view of
 // a single, globally-sorted list
 type Merger struct {
-	pattern *Pattern
-	lists   [][]Result
-	merged  []Result
-	chunks  *[]*Chunk
-	cursors []int
-	sorted  bool
-	tac     bool
-	final   bool
-	count   int
-	pass    bool
+	pattern  *Pattern
+	lists    [][]Result
+	merged   []Result
+	chunks   *[]*Chunk
+	cursors  []int
+	sorted   bool
+	tac      bool
+	final    bool
+	count    int
+	pass     bool
+	revision int
 }
 
 // PassMerger returns a new Merger that simply returns the items in the
 // original order
-func PassMerger(chunks *[]*Chunk, tac bool) *Merger {
+func PassMerger(chunks *[]*Chunk, tac bool, revision int) *Merger {
 	mg := Merger{
-		pattern: nil,
-		chunks:  chunks,
-		tac:     tac,
-		count:   0,
-		pass:    true}
+		pattern:  nil,
+		chunks:   chunks,
+		tac:      tac,
+		count:    0,
+		pass:     true,
+		revision: revision}
 
 	for _, chunk := range *mg.chunks {
 		mg.count += chunk.count
@@ -37,17 +41,18 @@ func PassMerger(chunks *[]*Chunk, tac bool) *Merger {
 }
 
 // NewMerger returns a new Merger
-func NewMerger(pattern *Pattern, lists [][]Result, sorted bool, tac bool) *Merger {
+func NewMerger(pattern *Pattern, lists [][]Result, sorted bool, tac bool, revision int) *Merger {
 	mg := Merger{
-		pattern: pattern,
-		lists:   lists,
-		merged:  []Result{},
-		chunks:  nil,
-		cursors: make([]int, len(lists)),
-		sorted:  sorted,
-		tac:     tac,
-		final:   false,
-		count:   0}
+		pattern:  pattern,
+		lists:    lists,
+		merged:   []Result{},
+		chunks:   nil,
+		cursors:  make([]int, len(lists)),
+		sorted:   sorted,
+		tac:      tac,
+		final:    false,
+		count:    0,
+		revision: revision}
 
 	for _, list := range mg.lists {
 		mg.count += len(list)
@@ -55,6 +60,11 @@ func NewMerger(pattern *Pattern, lists [][]Result, sorted bool, tac bool) *Merge
 	return &mg
 }
 
+// Revision returns revision number
+func (mg *Merger) Revision() int {
+	return mg.revision
+}
+
 // Length returns the number of items
 func (mg *Merger) Length() int {
 	return mg.count
diff --git a/src/merger_test.go b/src/merger_test.go
index c6af4f66..5894bea0 100644
--- a/src/merger_test.go
+++ b/src/merger_test.go
@@ -57,7 +57,7 @@ func TestMergerUnsorted(t *testing.T) {
 	cnt := len(items)
 
 	// Not sorted: same order
-	mg := NewMerger(nil, lists, false, false)
+	mg := NewMerger(nil, lists, false, false, 0)
 	assert(t, cnt == mg.Length(), "Invalid Length")
 	for i := 0; i < cnt; i++ {
 		assert(t, items[i] == mg.Get(i), "Invalid Get")
@@ -69,7 +69,7 @@ func TestMergerSorted(t *testing.T) {
 	cnt := len(items)
 
 	// Sorted sorted order
-	mg := NewMerger(nil, lists, true, false)
+	mg := NewMerger(nil, lists, true, false, 0)
 	assert(t, cnt == mg.Length(), "Invalid Length")
 	sort.Sort(ByRelevance(items))
 	for i := 0; i < cnt; i++ {
@@ -79,7 +79,7 @@ func TestMergerSorted(t *testing.T) {
 	}
 
 	// Inverse order
-	mg2 := NewMerger(nil, lists, true, false)
+	mg2 := NewMerger(nil, lists, true, false, 0)
 	for i := cnt - 1; i >= 0; i-- {
 		if items[i] != mg2.Get(i) {
 			t.Error("Not sorted", items[i], mg2.Get(i))
diff --git a/src/terminal.go b/src/terminal.go
index 7f6adade..3179d929 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -228,6 +228,7 @@ type Terminal struct {
 	merger             *Merger
 	selected           map[int32]selectedItem
 	version            int64
+	revision           int
 	reqBox             *util.EventBox
 	initialPreviewOpts previewOpts
 	previewOpts        previewOpts
@@ -644,7 +645,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		jumpLabels:         opts.JumpLabels,
 		printer:            opts.Printer,
 		printsep:           opts.PrintSep,
-		merger:             EmptyMerger,
+		merger:             EmptyMerger(0),
 		selected:           make(map[int32]selectedItem),
 		reqBox:             util.NewEventBox(),
 		initialPreviewOpts: opts.Preview,
@@ -930,9 +931,10 @@ func (t *Terminal) UpdateProgress(progress float32) {
 }
 
 // UpdateList updates Merger to display the list
-func (t *Terminal) UpdateList(merger *Merger, reset bool) {
+func (t *Terminal) UpdateList(merger *Merger) {
 	t.mutex.Lock()
 	var prevIndex int32 = -1
+	reset := t.revision != merger.Revision()
 	if !reset && t.track != trackDisabled {
 		if t.merger.Length() > 0 {
 			prevIndex = t.merger.Get(t.cy).item.Index()
@@ -944,6 +946,7 @@ func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 	t.merger = merger
 	if reset {
 		t.selected = make(map[int32]selectedItem)
+		t.revision = merger.Revision()
 		t.version++
 	}
 	if t.triggerLoad {
diff --git a/test/test_go.rb b/test/test_go.rb
index 469d007e..5ac0eee0 100755
--- a/test/test_go.rb
+++ b/test/test_go.rb
@@ -2935,6 +2935,14 @@ class TestGoFZF < TestBase
     tmux.send_keys "sleep 0.5 | #{FZF} --bind 'start:reload:ls' --bind 'load:become:tty'", :Enter
     tmux.until { |lines| assert_includes lines, '/dev/tty' }
   end
+
+  def test_disabled_preview_update
+    tmux.send_keys "echo bar | #{FZF} --disabled --bind 'change:reload:echo foo' --preview 'echo [{q}-{}]'", :Enter
+    tmux.until { |lines| assert_equal 1, lines.match_count }
+    tmux.until { |lines| assert(lines.any? { |line| line.include?('[-bar]') }) }
+    tmux.send_keys :x
+    tmux.until { |lines| assert(lines.any? { |line| line.include?('[x-foo]') }) }
+  end
 end
 
 module TestShell