mdbx: use MultiByteToWideChar(CP_THREAD_ACP) instead of mbstowcs().

src/core.c

@@ -12971,12 +12971,8 @@ __cold static int mdbx_handle_env_pathname(MDBX_handle_env_pathname *ctx,
     return MDBX_EINVAL;
 
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
+  const wchar_t *pathnameW = nullptr;
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
 
   const DWORD dwAttrib = GetFileAttributesW(pathnameW);
   if (dwAttrib == INVALID_FILE_ATTRIBUTES) {

src/mdbx.c++

@@ -216,26 +216,17 @@ MDBX_MAYBE_UNUSED PATH pchar_to_path(const char *c_str) {
 
 #if defined(_WIN32) || defined(_WIN64)
 
-#ifndef WC_ERR_INVALID_CHARS
-static const DWORD WC_ERR_INVALID_CHARS =
-    (6 /* Windows Vista */ <= /* MajorVersion */ LOBYTE(LOWORD(GetVersion())))
-        ? 0x00000080
-        : 0;
-#endif /* WC_ERR_INVALID_CHARS */
-
 template <> struct path_to_pchar<std::wstring> {
   std::string str;
   path_to_pchar(const std::wstring &path) {
     if (!path.empty()) {
-      const int chars =
+      const auto chars = mdbx_w2mb(nullptr, 0, path.data(), path.size());
-          WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, path.data(),
+      if (chars < 1)
-                              int(path.size()), nullptr, 0, nullptr, nullptr);
-      if (chars == 0)
         mdbx::error::throw_exception(GetLastError());
       str.append(chars, '\0');
-      WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, path.data(),
+      if (!mdbx_w2mb(const_cast<char *>(str.data()), chars, path.data(),
-                          int(path.size()), const_cast<char *>(str.data()),
+                     path.size()))
-                          chars, nullptr, nullptr);
+        mdbx::error::throw_exception(GetLastError());
     }
   }
   operator const char *() const { return str.c_str(); }
@@ -245,14 +236,14 @@ template <>
 MDBX_MAYBE_UNUSED std::wstring pchar_to_path<std::wstring>(const char *c_str) {
   std::wstring wstr;
   if (c_str && *c_str) {
-    const int chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, c_str,
+    const auto c_str_len = strlen(c_str);
-                                          int(strlen(c_str)), nullptr, 0);
+    const auto wchars = mdbx_mb2w(nullptr, 0, c_str, c_str_len);
-    if (chars == 0)
+    if (wchars < 1)
+      mdbx::error::throw_exception(GetLastError());
+    wstr.append(wchars, '\0');
+    if (!mdbx_mb2w(const_cast<wchar_t *>(wstr.data()), wchars, c_str,
+                   c_str_len))
       mdbx::error::throw_exception(GetLastError());
-    wstr.append(chars, '\0');
-    MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, c_str,
-                        int(strlen(c_str)), const_cast<wchar_t *>(wstr.data()),
-                        chars);
   }
   return wstr;
 }

src/osal.c

@@ -518,14 +518,35 @@ MDBX_INTERNAL_FUNC int mdbx_fastmutex_release(mdbx_fastmutex_t *fastmutex) {
 
 /*----------------------------------------------------------------------------*/
 
+#if defined(_WIN32) || defined(_WIN64)
+
+#ifndef WC_ERR_INVALID_CHARS
+static const DWORD WC_ERR_INVALID_CHARS =
+    (6 /* Windows Vista */ <= /* MajorVersion */ LOBYTE(LOWORD(GetVersion())))
+        ? 0x00000080
+        : 0;
+#endif /* WC_ERR_INVALID_CHARS */
+
+MDBX_INTERNAL_FUNC size_t mdbx_mb2w(wchar_t *dst, size_t dst_n, const char *src,
+                                    size_t src_n) {
+  return MultiByteToWideChar(CP_THREAD_ACP, MB_ERR_INVALID_CHARS, src,
+                             (int)src_n, dst, (int)dst_n);
+}
+
+MDBX_INTERNAL_FUNC size_t mdbx_w2mb(char *dst, size_t dst_n, const wchar_t *src,
+                                    size_t src_n) {
+  return WideCharToMultiByte(CP_THREAD_ACP, WC_ERR_INVALID_CHARS, src,
+                             (int)src_n, dst, (int)dst_n, nullptr, nullptr);
+}
+
+#endif /* Windows */
+
+/*----------------------------------------------------------------------------*/
+
 MDBX_INTERNAL_FUNC int mdbx_removefile(const char *pathname) {
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
+  const wchar_t *pathnameW = nullptr;
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
   return DeleteFileW(pathnameW) ? MDBX_SUCCESS : (int)GetLastError();
 #else
   return unlink(pathname) ? errno : MDBX_SUCCESS;
@@ -538,12 +559,8 @@ static bool is_valid_fd(int fd) { return !(isatty(fd) < 0 && errno == EBADF); }
 
 MDBX_INTERNAL_FUNC int mdbx_removedirectory(const char *pathname) {
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
+  const wchar_t *pathnameW = nullptr;
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
   return RemoveDirectoryW(pathnameW) ? MDBX_SUCCESS : (int)GetLastError();
 #else
   return rmdir(pathname) ? errno : MDBX_SUCCESS;
@@ -557,12 +574,8 @@ MDBX_INTERNAL_FUNC int mdbx_openfile(const enum mdbx_openfile_purpose purpose,
   *fd = INVALID_HANDLE_VALUE;
 
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
+  const wchar_t *pathnameW = nullptr;
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
 
   DWORD CreationDisposition = unix_mode_bits ? OPEN_ALWAYS : OPEN_EXISTING;
   DWORD FlagsAndAttributes =

src/osal.h

@@ -180,6 +180,11 @@ static inline void mdbx_free(void *ptr) { HeapFree(GetProcessHeap(), 0, ptr); }
 #define vsnprintf _vsnprintf /* ntdll */
 #endif
 
+MDBX_INTERNAL_FUNC size_t mdbx_mb2w(wchar_t *dst, size_t dst_n, const char *src,
+                                    size_t src_n);
+MDBX_INTERNAL_FUNC size_t mdbx_w2mb(char *dst, size_t dst_n, const wchar_t *src,
+                                    size_t src_n);
+
 #else /*----------------------------------------------------------------------*/
 
 typedef pthread_t mdbx_thread_t;
@@ -549,6 +554,20 @@ MDBX_INTERNAL_FUNC int mdbx_rpid_check(MDBX_env *env, uint32_t pid);
 
 #if defined(_WIN32) || defined(_WIN64)
 
+#define MUSTDIE_MB2WIDE(FROM, TO)                                              \
+  do {                                                                         \
+    const char *const from_tmp = (FROM);                                       \
+    const size_t from_mblen = strlen(from_tmp);                                \
+    const size_t to_wlen = mdbx_mb2w(nullptr, 0, from_tmp, from_mblen);        \
+    if (to_wlen < 1 || to_wlen > /* MAX_PATH */ INT16_MAX)                     \
+      return ERROR_INVALID_NAME;                                               \
+    wchar_t *const to_tmp = _alloca((to_wlen + 1) * sizeof(wchar_t));          \
+    if (to_wlen + 1 !=                                                         \
+        mdbx_mb2w(to_tmp, to_wlen + 1, from_tmp, from_mblen + 1))              \
+      return ERROR_INVALID_NAME;                                               \
+    (TO) = to_tmp;                                                             \
+  } while (0)
+
 typedef void(WINAPI *MDBX_srwlock_function)(MDBX_srwlock *);
 MDBX_INTERNAL_VAR MDBX_srwlock_function mdbx_srwlock_Init,
     mdbx_srwlock_AcquireShared, mdbx_srwlock_ReleaseShared,