Do not make assumptions about non existing entries in artifacts

internal/zipartifacts/metadata.go

@@ -10,12 +10,11 @@ import (
 	"path"
 	"sort"
 	"strconv"
-	"time"
 )
 
 type metadata struct {
-	Modified int64  `json:"modified"`
-	Mode     string `json:"mode"`
+	Modified int64  `json:"modified,omitempty"`
+	Mode     string `json:"mode,omitempty"`
 	CRC      uint32 `json:"crc,omitempty"`
 	Size     uint64 `json:"size,omitempty"`
 	Zipped   uint64 `json:"zipped,omitempty"`
@@ -26,6 +25,10 @@ const MetadataHeaderPrefix = "\x00\x00\x00&" // length of string below, encoded
 const MetadataHeader = "GitLab Build Artifacts Metadata 0.0.2\n"
 
 func newMetadata(file *zip.File) metadata {
+	if file == nil {
+		return metadata{}
+	}
+
 	return metadata{
 		Modified: file.ModTime().Unix(),
 		Mode:     strconv.FormatUint(uint64(file.Mode().Perm()), 8),
@@ -45,8 +48,8 @@ func (m metadata) writeEncoded(output io.Writer) error {
 	return writeBytes(output, j)
 }
 
-func writeZipEntryMetadata(output io.Writer, entry *zip.File) error {
-	if err := writeString(output, entry.Name); err != nil {
+func writeZipEntryMetadata(output io.Writer, path string, entry *zip.File) error {
+	if err := writeString(output, path); err != nil {
 		return err
 	}
 
@@ -58,12 +61,11 @@ func writeZipEntryMetadata(output io.Writer, entry *zip.File) error {
 }
 
 func generateZipMetadata(output io.Writer, archive *zip.Reader) error {
-	// Write metadata header
 	if err := writeString(output, MetadataHeader); err != nil {
 		return err
 	}
 
-	// Write empty error header
+	// Write empty error header that we may need in the future
 	if err := writeString(output, "{}"); err != nil {
 		return err
 	}
@@ -74,29 +76,17 @@ func generateZipMetadata(output io.Writer, archive *zip.Reader) error {
 	// Add missing entries
 	for _, entry := range archive.File {
 		zipMap[entry.Name] = entry
-		entryPath := entry.Name
 
-		for {
-			entryPath = path.Dir(entryPath)
+		for entryPath := path.Dir(entry.Name); entryPath != "." && entryPath != "/"; entryPath = path.Dir(entryPath) {
 			entryDir := entryPath + "/"
-			if entryPath == "." || entryPath == "/" {
-				break
-			}
-
 			if _, ok := zipMap[entryDir]; !ok {
-				var missingHeader zip.FileHeader
-				missingHeader.Name = entryDir
-				missingHeader.SetModTime(time.Now())
-				missingHeader.SetMode(os.FileMode(uint32(0755)))
-				missingEntry := &zip.File{FileHeader: missingHeader}
-
-				zipMap[entryDir] = missingEntry
+				zipMap[entryDir] = nil
 			}
 		}
 	}
 
 	// Sort paths
-	var sortedPaths []string
+	sortedPaths := make([]string, 0, len(zipMap))
 	for path, _ := range zipMap {
 		sortedPaths = append(sortedPaths, path)
 	}
@@ -104,7 +94,7 @@ func generateZipMetadata(output io.Writer, archive *zip.Reader) error {
 
 	// Write all files
 	for _, path := range sortedPaths {
-		if err := writeZipEntryMetadata(output, zipMap[path]); err != nil {
+		if err := writeZipEntryMetadata(output, path, zipMap[path]); err != nil {
 			return err
 		}
 	}