vaintroub · Sep 15, 2026
diff --git a/include/my_global.h b/include/my_global.h
@@ -568,8 +568,13 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #define O_SHORT_LIVED	0
 #endif
 #ifndef O_NOFOLLOW
+#ifdef _WIN32
+/* Not a genuine Windows open() flag, but implemented in my_win_open(). */
+#define O_NOFOLLOW      (1 << 28)
+#else
 #define O_NOFOLLOW      0
 #endif
+#endif
 #ifndef O_CLOEXEC
 #define O_CLOEXEC       0
 #endif

diff --git a/mysys/my_create.c b/mysys/my_create.c
@@ -41,7 +41,7 @@ File my_create(const char *FileName, mode_t CreateFlags, int access_flags,
   DBUG_PRINT("my",("Name: '%s' CreateFlags: %u  AccessFlags: %d  MyFlags: %lu",
 		   FileName, CreateFlags, access_flags, MyFlags));
 #if defined(_WIN32)
-  fd= my_win_open(FileName, access_flags | O_CREAT);
+  fd= my_win_open(FileName, access_flags | O_CREAT, MyFlags);
 #else
   fd= open((char *) FileName, access_flags | O_CREAT | O_CLOEXEC,
 	    CreateFlags ? CreateFlags : my_umask);

diff --git a/mysys/my_delete.c b/mysys/my_delete.c
@@ -19,7 +19,6 @@
 
 #ifdef _WIN32
 #include <direct.h> /* rmdir */
-static int my_win_unlink(const char *name);
 #endif
 
 CREATE_NOSYMLINK_FUNCTION(
@@ -35,7 +34,7 @@ int my_delete(const char *name, myf MyFlags)
   DBUG_PRINT("my",("name %s MyFlags %lu", name, MyFlags));
 
 #ifdef _WIN32
-  err = my_win_unlink(name);
+  err = my_win_unlink(name, MyFlags);
 #else
   if (MyFlags & MY_NOSYMLINKS)
     err= unlink_nosymlinks(name);
@@ -58,148 +57,6 @@ int my_delete(const char *name, myf MyFlags)
 } /* my_delete */
 
 
-#if defined (_WIN32)
-
-/* 
-  Delete file.
-
-  The function also makes best effort to minimize number of errors, 
-  where another program (or thread in the current program) has the the same file
-  open.
-
-  We're using several tricks to prevent the errors, such as
-
-  - Windows 10 "posix semantics" delete
-
-  - Avoid the error by using CreateFile() with FILE_FLAG_DELETE_ON_CLOSE, instead
-  of DeleteFile()
-
-  - If file which is deleted (delete on close) but has not entirely gone,
-  because it is still opened by some app, an attempt to trcreate file with the 
-  same name would  result in yet another error. The workaround here is renaming 
-  a file to unique name.
-
-  Symbolic link are deleted without renaming. Directories are not deleted.
-*/
-#include <my_rdtsc.h>
-
-static int my_win_unlink(const char *name)
-{
-  HANDLE handle= INVALID_HANDLE_VALUE;
-  DWORD attributes;
-  uint last_error;
-  char unique_filename[MAX_PATH + 35];
-  unsigned long long tsc; /* time stamp counter, for unique filename*/
-  int retries;
-  DBUG_ENTER("my_win_unlink");
-
-  DBUG_INJECT_FILE_SHARING_VIOLATION(name);
-
-  for (retries= FILE_SHARING_VIOLATION_RETRIES; ; retries--)
-  {
-    attributes= GetFileAttributes(name);
-    if (attributes == INVALID_FILE_ATTRIBUTES)
-    {
-      last_error= GetLastError();
-      DBUG_PRINT("error",
-                 ("GetFileAttributes(%s) failed with %u\n", name, last_error));
-      goto error;
-    }
-
-    if (attributes & FILE_ATTRIBUTE_DIRECTORY)
-    {
-      DBUG_PRINT("error", ("can't remove %s - it is a directory\n", name));
-      errno= EINVAL;
-      DBUG_RETURN(-1);
-    }
-
-    if (attributes & FILE_ATTRIBUTE_REPARSE_POINT)
-    {
-      /* Symbolic link. Delete link, the not target */
-      if (!DeleteFile(name))
-      {
-        last_error= GetLastError();
-        DBUG_PRINT("error",
-                   ("DeleteFile(%s) failed with %u\n", name, last_error));
-        goto error;
-      }
-      DBUG_RETURN(0);
-    }
-
-    /*
-      Try Windows 10 method, delete with "posix semantics" (file is not
-      visible, and creating a file with the same name won't fail, even if it
-      the file was open)
-    */
-    handle= CreateFile(name, DELETE,
-                       FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
-                       NULL, OPEN_EXISTING, 0, NULL);
-    if (handle != INVALID_HANDLE_VALUE)
-    {
-      /* 0x3 = FILE_DISPOSITION_FLAG_DELETE | FILE_DISPOSITION_FLAG_POSIX_SEMANTICS */
-      struct {DWORD _Flags;} disp= {0x3};
-      BOOL ok= SetFileInformationByHandle(
-          handle, (FILE_INFO_BY_HANDLE_CLASS) 21, &disp, sizeof(disp));
-      CloseHandle(handle);
-      if (ok)
-        DBUG_RETURN(0);
-    }
-
-    handle= CreateFile(name, DELETE, 0, NULL, OPEN_EXISTING,
-                       FILE_FLAG_DELETE_ON_CLOSE, NULL);
-    if (handle != INVALID_HANDLE_VALUE)
-    {
-      /*
-        We opened file without sharing flags (exclusive), no one else has this
-        file opened, thus it is safe to close handle to remove it. No renaming
-        is necessary.
-      */
-      CloseHandle(handle);
-      DBUG_RETURN(0);
-    }
-
-    /*
-       Can't open file exclusively, hence the file must be already opened by
-       someone else. Open it for delete (with all FILE_SHARE flags set),
-       rename to unique name, close.
-    */
-    handle= CreateFile(name, DELETE,
-                       FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
-                       NULL, OPEN_EXISTING, FILE_FLAG_DELETE_ON_CLOSE, NULL);
-    if (handle == INVALID_HANDLE_VALUE)
-    {
-      last_error= GetLastError();
-      DBUG_PRINT(
-          "error",
-          ("CreateFile(%s) with FILE_FLAG_DELETE_ON_CLOSE failed with %u\n",
-           name, last_error));
-      goto error;
-    }
-
-    tsc= my_timer_cycles();
-    my_snprintf(unique_filename, sizeof(unique_filename), "%s.%llx.deleted",
-                name, tsc);
-    if (!MoveFile(name, unique_filename))
-    {
-      DBUG_PRINT("warning",
-                 ("moving %s to unique filename failed, error %lu\n", name,
-                  GetLastError()));
-    }
-    CloseHandle(handle);
-    DBUG_RETURN(0);
-
-error:
-    if (last_error != ERROR_SHARING_VIOLATION || retries == 0)
-    {
-      my_osmaperr(last_error);
-      DBUG_RETURN(-1);
-    }
-    DBUG_CLEAR_FILE_SHARING_VIOLATION();
-    Sleep(FILE_SHARING_VIOLATION_DELAY_MS);
-  }
-}
-#endif
-
 /*
    Remove directory recursively.
 */

diff --git a/mysys/my_open.c b/mysys/my_open.c
@@ -47,10 +47,11 @@ File my_open(const char *FileName, int Flags, myf MyFlags)
   DBUG_ENTER("my_open");
   DBUG_PRINT("my",("Name: '%s'  Flags: %d  MyFlags: %lu",
 		   FileName, Flags, MyFlags));
+  DBUG_ASSERT(!(MyFlags & MY_NOSYMLINKS) || !(Flags & (O_CREAT | O_TRUNC)));
   if (!(MyFlags & (MY_WME | MY_FAE | MY_FFNF)))
     MyFlags|= my_global_flags;
 #if defined(_WIN32)
-  fd= my_win_open(FileName, Flags);
+  fd= my_win_open(FileName, Flags, MyFlags);
 #else
   if (MyFlags & MY_NOSYMLINKS)
     fd = open_nosymlinks(FileName, Flags | O_CLOEXEC, my_umask);

diff --git a/mysys/my_symlink.c b/mysys/my_symlink.c
@@ -136,9 +136,9 @@ int my_is_symlink(const char *filename __attribute__((unused)))
   'filename'.
 
   On error returns -1, unless error is file not found, in which case it
-  is 1; 'to' will then be populated with a fallback value as specified by
-  my_load_path() with null own_path_prefix; symlinks will not be
-  resolved.
+  is 1; 'to' will then be populated with a fallback value (on POSIX, as
+  specified by my_load_path() with null own_path_prefix; on Windows, see
+  my_win_realpath()); symlinks will not be resolved.
 
   Sets my_errno to specific error number.
 */
@@ -176,20 +176,7 @@ int my_realpath(char *to, const char *filename, myf MyFlags)
   }
   DBUG_RETURN(result);
 #elif defined(_WIN32)
-  int ret= GetFullPathName(filename,FN_REFLEN, to, NULL);
-  if (ret == 0 || ret > FN_REFLEN)
-  {
-    my_errno= (ret > FN_REFLEN) ? ENAMETOOLONG : GetLastError();
-    if (MyFlags & MY_WME)
-      my_error(EE_REALPATH, MYF(0), filename, my_errno);
-    /* 
-      GetFullPathName didn't work : use my_load_path() which is a poor 
-      substitute original name but will at least be able to resolve 
-      paths that starts with '.'.
-    */  
-    my_load_path(to, filename, NullS);
-    return -1;
-  }
+  return my_win_realpath(to, filename, MyFlags);
 #else
   my_load_path(to, filename, NullS);
 #endif