From: Joel Rosdahl <joel@rosdahl.net>
Date: Wed, 6 Nov 2024 20:51:00 +0000 (+0100)
Subject: fix: Fix util::make_relative_path for trailing slash on Windows
X-Git-Tag: v4.11~52
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d3a0adf732a9b834eece077b9dfcaf4ff7bd061b;p=thirdparty%2Fccache.git

fix: Fix util::make_relative_path for trailing slash on Windows

Given an existing directory called "example", std::filesystem apparently
behaves like this on Windows:

    std::filesystem::exists("example")                  -> true
    std::filesystem::exists("example/")                 -> true
    std::filesystem::exists("example\\")                -> true
    std::filesystem::equivalent("example", "example")   -> true
    std::filesystem::equivalent("example", "example/")  -> false
    std::filesystem::equivalent("example", "example\\") -> false

That's... well, unexpected. This makes util::make_relative_path buggy.
Fix this by pruning the trailing slash after normalizing the path.

Fixes #1518.
---

diff --git a/src/ccache/util/path.cpp b/src/ccache/util/path.cpp
index 93f703b9..83db436b 100644
--- a/src/ccache/util/path.cpp
+++ b/src/ccache/util/path.cpp
@@ -77,6 +77,11 @@ make_relative_path(const fs::path& actual_cwd,
   DEBUG_ASSERT(path.is_absolute());
 
   fs::path normalized_path = path.lexically_normal();
+  if (!normalized_path.has_filename()) {
+    // Skip trailing slash since fs::equivalent doesn't work otherwise on
+    // Windows.
+    normalized_path = normalized_path.parent_path();
+  }
   fs::path closest_existing_path = normalized_path;
   std::vector<fs::path> relpath_candidates;
   fs::path path_suffix;
diff --git a/unittest/test_util_path.cpp b/unittest/test_util_path.cpp
index 83425c4c..0f2d8876 100644
--- a/unittest/test_util_path.cpp
+++ b/unittest/test_util_path.cpp
@@ -101,6 +101,8 @@ TEST_CASE("util::make_relative_path")
 
   SUBCASE("Match of actual CWD")
   {
+    REQUIRE(fs::create_directory("d"));
+
     CHECK(make_relative_path(actual_cwd, apparent_cwd, actual_cwd + "/x")
           == "x");
     CHECK(make_relative_path(actual_cwd, apparent_cwd, actual_cwd + "/d")