From 0e3cf9862eef4abab498beae03449047aace93a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Mon, 2 Jan 2023 22:07:14 +0100
Subject: [PATCH] ComputePathTo: Handle case where from == to.

---
 Common/File/Path.cpp  |  5 +++++
 UI/MemStickScreen.cpp | 10 +++++++---
 unittest/UnitTest.cpp |  3 +++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Common/File/Path.cpp b/Common/File/Path.cpp
index 39a31e164e..489ab692b4 100644
--- a/Common/File/Path.cpp
+++ b/Common/File/Path.cpp
@@ -346,6 +346,11 @@ bool Path::IsAbsolute() const {
 }
 
 bool Path::ComputePathTo(const Path &other, std::string &path) const {
+	if (other == *this) {
+		path.clear();
+		return true;
+	}
+
 	if (!other.StartsWith(*this)) {
 		// Can't do this. Should return an error.
 		return false;
diff --git a/UI/MemStickScreen.cpp b/UI/MemStickScreen.cpp
index 78c4cf24fd..374c4683a0 100644
--- a/UI/MemStickScreen.cpp
+++ b/UI/MemStickScreen.cpp
@@ -507,15 +507,19 @@ static bool ListFileSuffixesRecursively(const Path &root, Path folder, std::vect
 		if (file.isDirectory) {
 			std::string dirSuffix;
 			if (root.ComputePathTo(file.fullName, dirSuffix)) {
-				dirSuffixes.push_back(dirSuffix);
-				ListFileSuffixesRecursively(root, folder / file.name, dirSuffixes, fileSuffixes);
+				if (!dirSuffix.empty()) {
+					dirSuffixes.push_back(dirSuffix);
+					ListFileSuffixesRecursively(root, folder / file.name, dirSuffixes, fileSuffixes);
+				}
 			} else {
 				ERROR_LOG_REPORT(SYSTEM, "Failed to compute PathTo from '%s' to '%s'", root.c_str(), folder.c_str());
 			}
 		} else {
 			std::string fileSuffix;
 			if (root.ComputePathTo(file.fullName, fileSuffix)) {
-				fileSuffixes.push_back(FileSuffix{ fileSuffix, file.size });
+				if (!fileSuffix.empty()) {
+					fileSuffixes.push_back(FileSuffix{ fileSuffix, file.size });
+				}
 			}
 		}
 	}
diff --git a/unittest/UnitTest.cpp b/unittest/UnitTest.cpp
index 1284584607..05d2d35475 100644
--- a/unittest/UnitTest.cpp
+++ b/unittest/UnitTest.cpp
@@ -661,6 +661,9 @@ static bool TestPath() {
 	EXPECT_TRUE(Path("/").ComputePathTo(Path("/home/foo/bar"), computedPath));
 	EXPECT_EQ_STR(computedPath, std::string("home/foo/bar"));
 
+	EXPECT_TRUE(Path("/a/b").ComputePathTo(Path("/a/b"), computedPath));
+	EXPECT_EQ_STR(computedPath, std::string());
+
 	return true;
 }