Merge #15270: Pull leveldb subtree

4f2e6c8b881b7ccda36233332dfd1bd231389a8e Squashed 'src/leveldb/' changes from 524b7e36a8..f545dfabff (MarcoFalke)

Pull request description:

  Some windows-related fixes.

  Sanity check with:

  ```
  git fetch https://github.com/bitcoin-core/leveldb
  ./test/lint/git-subtree-check.sh src/leveldb

Tree-SHA512: ff94907ff3075b81cffb733129673a9bfd2abbe84240686b29274382b64b4e5845880236458043d6db0332bf70d12942d9c0e68b4fffab43931103d224cb59d4

3 files changed, 22 insertions, 12 deletions

diff --git a/src/leveldb/db/c.cc b/src/leveldb/db/c.cc
index 08ff0ad90a..b23e3dcc9d 100644
--- a/src/leveldb/db/c.cc
+++ b/src/leveldb/db/c.cc
@@ -5,7 +5,9 @@
 #include "leveldb/c.h"
 
 #include <stdlib.h>
+#ifndef WIN32
 #include <unistd.h>
+#endif
 #include "leveldb/cache.h"
 #include "leveldb/comparator.h"
 #include "leveldb/db.h"
diff --git a/src/leveldb/port/port_win.h b/src/leveldb/port/port_win.h
index e8bf46ef27..989c15cd91 100644
--- a/src/leveldb/port/port_win.h
+++ b/src/leveldb/port/port_win.h
@@ -32,9 +32,16 @@
 #define STORAGE_LEVELDB_PORT_PORT_WIN_H_
 
 #ifdef _MSC_VER
+#if !(_MSC_VER >= 1900)
 #define snprintf _snprintf
+#endif
 #define close _close
 #define fread_unlocked _fread_nolock
+#ifdef _WIN64
+#define ssize_t int64_t
+#else
+#define ssize_t int32_t
+#endif
 #endif
 
 #include <string>
diff --git a/src/leveldb/util/env_win.cc b/src/leveldb/util/env_win.cc
index 81380216bb..830332abe9 100644
--- a/src/leveldb/util/env_win.cc
+++ b/src/leveldb/util/env_win.cc
@@ -203,24 +203,16 @@ public:
 
 void ToWidePath(const std::string& value, std::wstring& target) {
 	wchar_t buffer[MAX_PATH];
-	MultiByteToWideChar(CP_ACP, 0, value.c_str(), -1, buffer, MAX_PATH);
+	MultiByteToWideChar(CP_UTF8, 0, value.c_str(), -1, buffer, MAX_PATH);
 	target = buffer;
 }
 
 void ToNarrowPath(const std::wstring& value, std::string& target) {
 	char buffer[MAX_PATH];
-	WideCharToMultiByte(CP_ACP, 0, value.c_str(), -1, buffer, MAX_PATH, NULL, NULL);
+	WideCharToMultiByte(CP_UTF8, 0, value.c_str(), -1, buffer, MAX_PATH, NULL, NULL);
 	target = buffer;
 }
 
-std::string GetCurrentDir()
-{
-    CHAR path[MAX_PATH];
-    ::GetModuleFileNameA(::GetModuleHandleA(NULL),path,MAX_PATH);
-    *strrchr(path,'\\') = 0;
-    return std::string(path);
-}
-
 std::wstring GetCurrentDirW()
 {
     WCHAR path[MAX_PATH];
@@ -229,6 +221,13 @@ std::wstring GetCurrentDirW()
     return std::wstring(path);
 }
 
+std::string GetCurrentDir()
+{
+    std::string path;
+    ToNarrowPath(GetCurrentDirW(), path);
+    return path;
+}
+
 std::string& ModifyPath(std::string& path)
 {
     if(path[0] == '/' || path[0] == '\\'){
@@ -764,14 +763,16 @@ uint64_t Win32Env::NowMicros()
 static Status CreateDirInner( const std::string& dirname )
 {
     Status sRet;
-    DWORD attr = ::GetFileAttributes(dirname.c_str());
+    std::wstring dirnameW;
+    ToWidePath(dirname, dirnameW);
+    DWORD attr = ::GetFileAttributesW(dirnameW.c_str());
     if (attr == INVALID_FILE_ATTRIBUTES) { // doesn't exist:
       std::size_t slash = dirname.find_last_of("\\");
       if (slash != std::string::npos){
 	sRet = CreateDirInner(dirname.substr(0, slash));
 	if (!sRet.ok()) return sRet;
       }
-      BOOL result = ::CreateDirectory(dirname.c_str(), NULL);
+      BOOL result = ::CreateDirectoryW(dirnameW.c_str(), NULL);
       if (result == FALSE) {
 	sRet = Status::IOError(dirname, "Could not create directory.");
 	return sRet;