Move ignore handling from index recv to puller (fixes #1133)

With this change we accept updates for ignored files from other devices,
and check the ignore patterns at pull time. When we detect that the
ignore patterns have changed we do a full check of files that we might
now need to pull.

internal/model/model.go

@@ -452,7 +452,6 @@ func (m *Model) Index(deviceID protocol.DeviceID, folder string, fs []protocol.F
 
 	m.fmut.RLock()
 	files, ok := m.folderFiles[folder]
-	ignores, _ := m.folderIgnores[folder]
 	m.fmut.RUnlock()
 
 	if !ok {
@@ -461,9 +460,9 @@ func (m *Model) Index(deviceID protocol.DeviceID, folder string, fs []protocol.F
 
 	for i := 0; i < len(fs); {
 		lamport.Default.Tick(fs[i].Version)
-		if (ignores != nil && ignores.Match(fs[i].Name)) || symlinkInvalid(fs[i].IsSymlink()) {
+		if symlinkInvalid(fs[i].IsSymlink()) {
 			if debug {
-				l.Debugln("dropping update for ignored/unsupported symlink", fs[i])
+				l.Debugln("dropping update for unsupported symlink", fs[i])
 			}
 			fs[i] = fs[len(fs)-1]
 			fs = fs[:len(fs)-1]
@@ -496,7 +495,6 @@ func (m *Model) IndexUpdate(deviceID protocol.DeviceID, folder string, fs []prot
 
 	m.fmut.RLock()
 	files, ok := m.folderFiles[folder]
-	ignores, _ := m.folderIgnores[folder]
 	m.fmut.RUnlock()
 
 	if !ok {
@@ -505,9 +503,9 @@ func (m *Model) IndexUpdate(deviceID protocol.DeviceID, folder string, fs []prot
 
 	for i := 0; i < len(fs); {
 		lamport.Default.Tick(fs[i].Version)
-		if (ignores != nil && ignores.Match(fs[i].Name)) || symlinkInvalid(fs[i].IsSymlink()) {
+		if symlinkInvalid(fs[i].IsSymlink()) {
 			if debug {
-				l.Debugln("dropping update for ignored/unsupported symlink", fs[i])
+				l.Debugln("dropping update for unsupported symlink", fs[i])
 			}
 			fs[i] = fs[len(fs)-1]
 			fs = fs[:len(fs)-1]

internal/model/puller.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/syncthing/syncthing/internal/config"
 	"github.com/syncthing/syncthing/internal/events"
+	"github.com/syncthing/syncthing/internal/ignore"
 	"github.com/syncthing/syncthing/internal/osutil"
 	"github.com/syncthing/syncthing/internal/protocol"
 	"github.com/syncthing/syncthing/internal/scanner"
@@ -100,6 +101,7 @@ func (p *Puller) Serve() {
 	}()
 
 	var prevVer uint64
+	var prevIgnoreHash string
 
 	// We don't start pulling files until a scan has been completed.
 	initialScanCompleted := false
@@ -125,6 +127,20 @@ loop:
 				continue
 			}
 
+			p.model.fmut.RLock()
+			curIgnores := p.model.folderIgnores[p.folder]
+			p.model.fmut.RUnlock()
+
+			if newHash := curIgnores.Hash(); newHash != prevIgnoreHash {
+				// The ignore patterns have changed. We need to re-evaluate if
+				// there are files we need now that were ignored before.
+				if debug {
+					l.Debugln(p, "ignore patterns have changed, resetting prevVer")
+				}
+				prevVer = 0
+				prevIgnoreHash = newHash
+			}
+
 			// RemoteLocalVersion() is a fast call, doesn't touch the database.
 			curVer := p.model.RemoteLocalVersion(p.folder)
 			if curVer == prevVer {
@@ -149,7 +165,7 @@ loop:
 					checksum = true
 				}
 
-				changed := p.pullerIteration(checksum)
+				changed := p.pullerIteration(checksum, curIgnores)
 				if debug {
 					l.Debugln(p, "changed", changed)
 				}
@@ -167,7 +183,7 @@ loop:
 						// them, but at the same time we have the local
 						// version that includes those files in curVer. So we
 						// catch the case that localVersion might have
-						// decresed here.
+						// decreased here.
 						l.Debugln(p, "adjusting curVer", lv)
 						curVer = lv
 					}
@@ -233,7 +249,7 @@ func (p *Puller) String() string {
 // returns the number items that should have been synced (even those that
 // might have failed). One puller iteration handles all files currently
 // flagged as needed in the folder.
-func (p *Puller) pullerIteration(checksum bool) int {
+func (p *Puller) pullerIteration(checksum bool, ignores *ignore.Matcher) int {
 	pullChan := make(chan pullBlockState)
 	copyChan := make(chan copyBlocksState)
 	finisherChan := make(chan *sharedPullerState)
@@ -298,6 +314,11 @@ func (p *Puller) pullerIteration(checksum bool) int {
 
 		file := intf.(protocol.FileInfo)
 
+		if ignores.Match(file.Name) {
+			// This is an ignored file. Skip it, continue iteration.
+			return true
+		}
+
 		events.Default.Log(events.ItemStarted, map[string]string{
 			"folder": p.folder,
 			"item":   file.Name,