grass.mapcalc: Fix mapcalc wrapper random seeding

python/grass/script/raster.py

@@ -22,7 +22,6 @@
 
 import os
 import string
-import time
 from pathlib import Path
 
 from .core import (
@@ -135,14 +134,14 @@ def mapcalc(
     :param bool verbose: True to run verbosely (``--v``)
     :param bool overwrite: True to enable overwriting the output (``--o``)
     :param seed: an integer used to seed the random-number generator for the
-                 rand() function, or 'auto' to generate a random seed
+                 rand() function. If not provided, r.mapcalc uses automatic seeding.
     :param nprocs: Number of threads for parallel computing
     :param dict env: dictionary of environment variables for child process
     :param kwargs:
     """
-
+    # Handle backwards compatibility: convert seed="auto" to None
     if seed == "auto":
-        seed = hash((os.getpid(), time.time())) % (2**32)
+        seed = None
 
     t = string.Template(exp)
     e = t.substitute(**kwargs)
@@ -210,16 +209,16 @@ def mapcalc_start(
     :param bool verbose: True to run verbosely (``--v``)
     :param bool overwrite: True to enable overwriting the output (``--o``)
     :param seed: an integer used to seed the random-number generator for the
-                 rand() function, or 'auto' to generate a random seed
+                 rand() function. If not provided, r.mapcalc uses automatic seeding.
     :param nprocs: Number of threads for parallel computing
     :param dict env: dictionary of environment variables for child process
     :param kwargs:
 
     :return: Popen object
     """
-
+    # Handle backwards compatibility: convert seed="auto" to None
     if seed == "auto":
-        seed = hash((os.getpid(), time.time())) % (2**32)
+        seed = None
 
     t = string.Template(exp)
     e = t.substitute(**kwargs)