absPath(): Use std::optional

(cherry picked from commit 1bf9eb21b75f0d93d9c1633ea2e6fdf840047e79)

1 files changed, 3 insertions, 3 deletions

diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 52a1394f2..097ff210a 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -97,10 +97,10 @@ void replaceEnv(std::map<std::string, std::string> newEnv)
 }
 
 
-Path absPath(Path path, Path dir)
+Path absPath(Path path, std::optional<Path> dir)
 {
     if (path[0] != '/') {
-        if (dir == "") {
+        if (!dir) {
 #ifdef __GNU__
             /* GNU (aka. GNU/Hurd) doesn't have any limitation on path
                lengths and doesn't define `PATH_MAX'.  */
@@ -116,7 +116,7 @@ Path absPath(Path path, Path dir)
             free(buf);
 #endif
         }
-        path = dir + "/" + path;
+        path = *dir + "/" + path;
     }
     return canonPath(path);
 }