feature: add --KeepMissing option to chkbit update command.

cmd/chkbit/main.go

@@ -80,6 +80,7 @@ type CLI struct {
 		Paths        []string `arg:"" name:"paths" help:"directories to update"`
 		SkipExisting bool     `short:"s" help:"only add new and modified files, do not check existing (quicker)"`
 		Force        bool     `help:"force update of damaged items (advanced usage only)"`
+		KeepMissing  bool     `help:"keep missing files in the index"`
 	} `cmd:"" help:"add and update modified files, also checking existing ones (see chkbit update -h)"`
 
 	Init struct {
@@ -327,6 +328,7 @@ func (m *Main) runCmd(command string, cli CLI) int {
 		m.context.UpdateIndex = true
 		m.context.UpdateSkipCheck = cli.Update.SkipExisting
 		m.context.ForceUpdateDmg = cli.Update.Force
+		m.context.KeepMissing = cli.Update.KeepMissing
 		m.log("chkbit update " + strings.Join(pathList, ", "))
 	case cmdShowIgnored:
 		pathList = cli.ShowIgnored.Paths

context.go

@@ -15,6 +15,7 @@ type Context struct {
 	UpdateIndex        bool // add and update hashes
 	UpdateSkipCheck    bool // do not check existing hashes when updating
 	ShowIgnoredOnly    bool // print ignored files
+	KeepMissing        bool // keep missing files in index when updating
 	LogDeleted         bool // output deleted files and directories
 	IncludeDot         bool // include dot files
 	ForceUpdateDmg     bool

index.go

@@ -169,9 +169,15 @@ func (i *Index) checkFix(forceUpdateDmg bool) {
 	// track deleted files
 	for name := range i.cur {
 		if _, ok := i.new[name]; !ok {
-			i.modified = true
-			if i.context.LogDeleted {
-				i.logFile(StatusDeleted, name)
+			// file missing
+			if i.context.KeepMissing {
+				// preserve old entry
+				i.new[name] = i.cur[name]
+			} else {
+				i.modified = true
+				if i.context.LogDeleted {
+					i.logFile(StatusDeleted, name)
+				}
 			}
 		}
 	}
@@ -183,9 +189,15 @@ func (i *Index) checkFix(forceUpdateDmg bool) {
 	}
 	for _, name := range i.curDirList {
 		if !m[name] {
-			i.modified = true
-			if i.context.LogDeleted {
-				i.logDir(StatusDeleted, name+"/")
+			// directory missing
+			if i.context.KeepMissing {
+				// preserve old directory
+				i.newDirList = append(i.newDirList, name)
+			} else {
+				i.modified = true
+				if i.context.LogDeleted {
+					i.logDir(StatusDeleted, name+"/")
+				}
 			}
 		}
 	}