1 files changed, 50 insertions, 2 deletions

diff --git a/src/libutil/filesystem.cc b/src/libutil/filesystem.cc
index cf99b848a..198db2832 100644
--- a/src/libutil/filesystem.cc
+++ b/src/libutil/filesystem.cc
@@ -43,6 +43,53 @@ void replaceSymlink(const Path & target, const Path & link,
     }
 }
 
+void setWriteTime(const fs::path & p, const struct stat & st)
+{
+    struct timeval times[2];
+    times[0] = {
+        .tv_sec = st.st_atime,
+        .tv_usec = 0,
+    };
+    times[1] = {
+        .tv_sec = st.st_mtime,
+        .tv_usec = 0,
+    };
+    warn("Setting the mtime of %s to %d", p.c_str(), st.st_mtim.tv_sec);
+    if (lutimes(p.c_str(), times) != 0)
+        throw SysError("changing modification time of '%s'", p);
+}
+
+void copy(const fs::directory_entry & from, const fs::path & to, bool andDelete)
+{
+    // TODO: Rewrite the `is_*` to use `symlink_status()`
+    auto statOfFrom = lstat(from.path().c_str());
+    auto fromStatus = from.symlink_status();
+
+    // Mark the directory as writable so that we can delete its children
+    if (andDelete && fs::is_directory(fromStatus)) {
+        fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow);
+    }
+
+
+    if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) {
+        fs::copy(from.path(), to, fs::copy_options::copy_symlinks | fs::copy_options::overwrite_existing);
+    } else if (fs::is_directory(fromStatus)) {
+        fs::create_directory(to);
+        for (auto & entry : fs::directory_iterator(from.path())) {
+            copy(entry, to / entry.path().filename(), andDelete);
+        }
+    } else {
+        throw Error("file '%s' has an unsupported type", from.path());
+    }
+
+    setWriteTime(to, statOfFrom);
+    if (andDelete) {
+        if (!fs::is_symlink(fromStatus))
+            fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow);
+        fs::remove(from.path());
+    }
+}
+
 void moveFile(const Path & oldName, const Path & newName)
 {
     auto oldPath = fs::path(oldName);
@@ -51,8 +98,9 @@ void moveFile(const Path & oldName, const Path & newName)
         fs::rename(oldPath, newPath);
     } catch (fs::filesystem_error & e) {
         if (e.code().value() == EXDEV) {
-            fs::copy(oldName, newName, fs::copy_options::copy_symlinks);
-            fs::remove_all(oldName);
+            fs::remove(newPath);
+            warn("Copying %s to %s", oldName, newName);
+            copy(fs::directory_entry(oldPath), newPath, true);
         }
     }
 }