Merge bitcoin/bitcoin#24308: util: use stronger-guarantee rename method

ee822d85d6de7db85416190cf843ad74147519cf util: use stronger-guarantee rename method (Vasil Dimov)

Pull request description:

  Use std::filesystem::rename() instead of std::rename(). We rely on the
  destination to be overwritten if it exists, but std::rename()'s behavior
  is implementation-defined in this case.

  This is a rebase of #20435 by vasild.

ACKs for top commit:
  MarcoFalke:
    review ACK ee822d85d6de7db85416190cf843ad74147519cf
  hebasto:
    Approach ACK ee822d85d6de7db85416190cf843ad74147519cf.
  vasild:
    ACK ee822d85d6de7db85416190cf843ad74147519cf

Tree-SHA512: 8f65f154d235c2704f18008d9d40ced3c5d84e4d55653aa70bde345066b6083c84667b5a2f4d69eeaad0bec6c607645e21ddd2bf85617bdec4a2e33752e2059a

2 files changed, 10 insertions, 7 deletions

diff --git a/src/util/system.cpp b/src/util/system.cpp
index 64d8ef38f0..5cef2be07a 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -74,6 +74,7 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <system_error>
 #include <thread>
 #include <typeinfo>
 
@@ -1061,13 +1062,9 @@ void ArgsManager::LogArgs() const
 
 bool RenameOver(fs::path src, fs::path dest)
 {
-#ifdef WIN32
-    return MoveFileExW(src.wstring().c_str(), dest.wstring().c_str(),
-                       MOVEFILE_REPLACE_EXISTING) != 0;
-#else
-    int rc = std::rename(src.c_str(), dest.c_str());
-    return (rc == 0);
-#endif /* WIN32 */
+    std::error_code error;
+    fs::rename(src, dest, error);
+    return !error;
 }
 
 /**
diff --git a/src/util/system.h b/src/util/system.h
index 6b7bd38cc2..a72ba3f3ed 100644
--- a/src/util/system.h
+++ b/src/util/system.h
@@ -69,7 +69,13 @@ void DirectoryCommit(const fs::path &dirname);
 bool TruncateFile(FILE *file, unsigned int length);
 int RaiseFileDescriptorLimit(int nMinFD);
 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
+
+/**
+ * Rename src to dest.
+ * @return true if the rename was successful.
+ */
 [[nodiscard]] bool RenameOver(fs::path src, fs::path dest);
+
 bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only=false);
 void UnlockDirectory(const fs::path& directory, const std::string& lockfile_name);
 bool DirIsWritable(const fs::path& directory);