[Windows] Reset mp_flag after each drive on `psutil.disk_partitions…

…()` (#1961)

CREDITS

@@ -754,3 +754,7 @@ C: Russia
 E: [email protected]
 W: https://gorbunov-dmitry.github.io
 D: fix typos in documentation
+
+N: Pablo Baeyens
+W: https://github.com/mx-psi
+I: 1598

HISTORY.rst

@@ -25,6 +25,8 @@ XXXX-XX-XX
 - 1921_: [Windows] psutil.swap_memory() shows committed memory instead of swap
 - 1953_: [Windows] disk_partitions() crashes due to insufficient buffer len.
   (patch by MaWe2019)
+- 1598_: [Windows] psutil.disk_partitions() only returns mountpoints on drives
+  where it first finds one
 
 5.8.0
 =====

psutil/arch/windows/disk.c

@@ -290,6 +290,7 @@ psutil_disk_partitions(PyObject *self, PyObject *args) {
                 mp_h = FindFirstVolumeMountPoint(
                     drive_letter, mp_buf, MAX_PATH);
                 if (mp_h != INVALID_HANDLE_VALUE) {
+                    mp_flag = TRUE;
                     while (mp_flag) {
                         // Append full mount path with drive letter
                         strcpy_s(mp_path, _countof(mp_path), drive_letter);