fix bug podman cp directory

`podman cp` used to copy the contents under the source directory to the destination. But according to the specification in podman-cp.md. it should copy the whole directory to the destination if the destination directory already exists.
- src dir ends with /., copy the contents to dest dir
- src dir does not end with /.
 - dest dir /home does not exist, copy the contents
 - dest dir /home exists, copy the directory

```
$ sudo podman cp /home/qiwan/Documents/empty 7c47:/home
$ sudo podman exec -it 7c47 ls /home
$

$ sudo podman cp /home/qiwan/Documents/empty 7c47:/home
$ sudo podman exec -it 7c47 ls /home
empty

```

Signed-off-by: Qi Wang <qiwan@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/cmd/podman/cp.go b/cmd/podman/cp.go
index a0dd46260..7dee37287 100644
--- a/cmd/podman/cp.go
+++ b/cmd/podman/cp.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -207,6 +208,11 @@ func copy(src, destPath, dest string, idMappingOpts storage.IDMappingOptions, ch
 	if !srcfi.IsDir() && !strings.HasSuffix(dest, string(os.PathSeparator)) {
 		destdir = filepath.Dir(destPath)
 	}
+	_, err = os.Stat(destdir)
+	if err != nil && !os.IsNotExist(err) {
+		return errors.Wrapf(err, "error checking directory %q", destdir)
+	}
+	destDirIsExist := (err == nil)
 	if err = os.MkdirAll(destdir, 0755); err != nil {
 		return errors.Wrapf(err, "error creating directory %q", destdir)
 	}
@@ -219,6 +225,9 @@ func copy(src, destPath, dest string, idMappingOpts storage.IDMappingOptions, ch
 	if srcfi.IsDir() {
 
 		logrus.Debugf("copying %q to %q", srcPath+string(os.PathSeparator)+"*", dest+string(os.PathSeparator)+"*")
+		if destDirIsExist && !strings.HasSuffix(src, fmt.Sprintf("%s.", string(os.PathSeparator))) {
+			destPath = filepath.Join(destPath, filepath.Base(srcPath))
+		}
 		if err = copyWithTar(srcPath, destPath); err != nil {
 			return errors.Wrapf(err, "error copying %q to %q", srcPath, dest)
 		}