From 13f574bfb24e5e483d97254f78724a13a8076021 Mon Sep 17 00:00:00 2001
From: Maarten ter Huurne <maarten@treewalker.org>
Date: Wed, 13 Aug 2014 07:35:29 +0200
Subject: [PATCH] Avoid moving around entries unless new ones were found

When scanning multiple directories in succession, it's possible that
in some of them no matches are found. Avoid moving all pre-existing
entries back and forth in that case.

Also use move instead of copy for transferring the pre-existing
entries from the vector to the set.
---
 src/filelister.cpp | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/filelister.cpp b/src/filelister.cpp
index d7f3e82..2ba6950 100644
--- a/src/filelister.cpp
+++ b/src/filelister.cpp
@@ -74,14 +74,10 @@ static void moveNames(set<string, case_less>&& from, vector<string>& to)
 
 void FileLister::browse(const string& path, bool clean)
 {
-	set<string, case_less> directorySet;
-	set<string, case_less> fileSet;
-	if (!clean) {
-		directorySet.insert(directories.begin(), directories.end());
-		fileSet.insert(files.begin(), files.end());
+	if (clean) {
+		directories.clear();
+		files.clear();
 	}
-	directories.clear();
-	files.clear();
 
 	string slashedPath = path;
 	if (path[path.length() - 1] != '/')
@@ -93,6 +89,9 @@ void FileLister::browse(const string& path, bool clean)
 		return;
 	}
 
+	set<string, case_less> directorySet;
+	set<string, case_less> fileSet;
+
 	while (struct dirent *dptr = readdir(dirp)) {
 		string file = dptr->d_name;
 
@@ -155,8 +154,21 @@ void FileLister::browse(const string& path, bool clean)
 
 	closedir(dirp);
 
-	moveNames(move(directorySet), directories);
-	moveNames(move(fileSet), files);
+	if (!directorySet.empty()) {
+		for (string& dir : directories) {
+			directorySet.emplace(move(dir));
+		}
+		directories.clear();
+		moveNames(move(directorySet), directories);
+	}
+
+	if (!fileSet.empty()) {
+		for (string& file : files) {
+			fileSet.emplace(move(file));
+		}
+		files.clear();
+		moveNames(move(fileSet), files);
+	}
 }
 
 unsigned int FileLister::size()