fix: include parent dirs when listing archive members

Zip archives can omit files' parent directories, as they will be
automatically created during extraction. When listing members from
a zip archive, ensure that all parent directories are included. This
guarantees that during charm cleanup, directories are not missed.

charmarchive.go

@@ -273,7 +273,16 @@ func (a *CharmArchive) ArchiveMembers() (set.Strings, error) {
 	if err != nil {
 		return set.NewStrings(), err
 	}
-	manifest := set.NewStrings(paths...)
+	manifest := set.NewStrings()
+	// Zip archives can omit file's parent directories,
+	// as these are created automatically during extraction.
+	// Ensure that parent directories exist in the member list.
+	for _, path := range paths {
+		for path != "." && path != "/" {
+			manifest.Add(path)
+			path = filepath.Dir(path)
+		}
+	}
 	// We always write out a revision file, even if there isn't one in the
 	// archive; and we always strip ".", because that's sometimes not present.
 	manifest.Add("revision")

charmarchive_test.go

@@ -7,6 +7,7 @@ import (
 	"archive/zip"
 	"bytes"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -221,6 +222,14 @@ func (s *CharmArchiveSuite) TestArchiveMembersSymlink(c *gc.C) {
 	c.Assert(manifest, gc.DeepEquals, set.NewStrings(expected...))
 }
 
+func (s *CharmArchiveSuite) TestArchiveMembersOmitDirs(c *gc.C) {
+	srcPath := cloneDir(c, charmDirPath(c, "dummy"))
+	archive := archiveDirOnlyFiles(c, srcPath)
+	manifest, err := archive.ArchiveMembers()
+	c.Assert(err, gc.IsNil)
+	c.Assert(manifest, gc.DeepEquals, set.NewStrings(dummyArchiveMembers...))
+}
+
 func (s *CharmArchiveSuite) TestExpandTo(c *gc.C) {
 	archive, err := charm.ReadCharmArchive(s.archivePath)
 	c.Assert(err, gc.IsNil)
@@ -475,3 +484,38 @@ func archiveDir(c *gc.C, dirpath string) *charm.CharmArchive {
 	c.Assert(err, gc.IsNil)
 	return archive
 }
+
+func archiveDirOnlyFiles(c *gc.C, dirpath string) *charm.CharmArchive {
+	dir, err := charm.ReadCharmDir(dirpath)
+	c.Assert(err, gc.IsNil)
+	buf := new(bytes.Buffer)
+	err = dir.ArchiveTo(buf)
+	r, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
+	c.Assert(err, gc.IsNil)
+	buf = new(bytes.Buffer)
+	w := zip.NewWriter(buf)
+	for _, f := range r.File {
+		if f.FileInfo().IsDir() {
+			continue
+		}
+		rf, err := f.Open()
+		if err != nil {
+			c.Assert(err, gc.IsNil)
+		}
+		wf, err := w.Create(f.Name)
+		if err != nil {
+			c.Assert(err, gc.IsNil)
+		}
+		_, err = io.Copy(wf, rf)
+		if err != nil {
+			c.Assert(err, gc.IsNil)
+		}
+	}
+	err = w.Close()
+	if err != nil {
+		c.Assert(err, gc.IsNil)
+	}
+	archive, err := charm.ReadCharmArchiveBytes(buf.Bytes())
+	c.Assert(err, gc.IsNil)
+	return archive
+}