Fix issue preventing includeed sources from being mapped to the rep…

…o root

Signed-off-by: Fred Heinecke <[email protected]>

internal/fs/fs.go

@@ -64,7 +64,7 @@ var (
 )
 
 // CopyDir recursively copies a directory tree, attempting to preserve permissions.
-// Source directory must exist, destination directory must *not* exist.
+// Source directory must exist.
 func CopyDir(src, dst string) error {
 	src = filepath.Clean(src)
 	dst = filepath.Clean(dst)
@@ -83,9 +83,6 @@ func CopyDir(src, dst string) error {
 	if err != nil && !os.IsNotExist(err) {
 		return err
 	}
-	if err == nil {
-		return errDstExist
-	}
 
 	if err = os.MkdirAll(dst, fi.Mode()); err != nil {
 		return fmt.Errorf("cannot mkdir %s: %w", dst, err)

internal/fs/rename.go

@@ -20,10 +20,12 @@ func renameFallback(err error, src, dst string) error {
 	// copy if we detect that case. syscall.EXDEV is the common name for the
 	// cross device link error which has varying output text across different
 	// operating systems.
+	// Rename may also fail if the directory already exists, which occurs when
+	// mapping to the root of another repo. Copy should still succeed.
 	terr, ok := err.(*os.LinkError)
 	if !ok {
 		return err
-	} else if terr.Err != syscall.EXDEV {
+	} else if terr.Err != syscall.EXDEV && terr.Err != syscall.EEXIST {
 		return fmt.Errorf("link error: cannot rename %s to %s: %w", src, dst, terr)
 	}