[FIX] core: consider x.y.z upgrade scripts as majorless

Also warn about invalid version numbers in upgrade scripts.

closes odoo/odoo#118420

Related: odoo/enterprise#39698
Related: odoo/upgrade#4554
Signed-off-by: Christophe Simonis <chs@odoo.com>
Co-authored-by: Alvaro Fuentes <afu@odoo.com>

odoo/modules/migration.py

@@ -8,6 +8,7 @@ import glob
 import importlib.util
 import logging
 import os
+import re
 from os.path import join as opj
 
 from odoo.modules.module import get_resource_path
@@ -18,6 +19,33 @@ from odoo.tools.parse_version import parse_version
 _logger = logging.getLogger(__name__)
 
 
+VERSION_RE = re.compile(
+    r"""^
+        # Optional prefix with Odoo version
+        ((
+            6\.1|
+
+            # "x.0" version, with x >= 6.
+            [6-9]\.0|
+
+            # multi digits "x.0" versions
+            [1-9]\d+\.0|
+
+            # x.saas~y, where x >= 7 and x <= 10
+            (7|8|9|10)\.saas~[1-9]\d*|
+
+            # saas~x.y, where x >= 11 and y between 1 and 9
+            # FIXME handle version >= saas~100 (expected in year 2106)
+            saas~(1[1-9]|[2-9]\d+)\.[1-9]
+        )\.)?
+        # After Odoo version we allow precisely 2 or 3 parts
+        # note this will also allow 0.0.0 which has a special meaning
+        \d+\.\d+(\.\d+)?
+    $""",
+    re.VERBOSE | re.ASCII,
+)
+
+
 def load_script(path, module_name):
     full_path = get_resource_path(*path.split(os.path.sep)) if not os.path.isabs(path) else path
     spec = importlib.util.spec_from_file_location(module_name, full_path)
@@ -71,13 +99,27 @@ class MigrationManager(object):
                 if os.path.exists(upgrade_path):
                     yield upgrade_path
 
+        def _verify_upgrade_version(path, version):
+            full_path = opj(path, version)
+            if not os.path.isdir(full_path):
+                return False
+
+            if version == "tests":
+                return False
+
+            if not VERSION_RE.match(version):
+                _logger.warning("Invalid version for upgrade script %r", full_path)
+                return False
+
+            return True
+
         def get_scripts(path):
             if not path:
                 return {}
             return {
                 version: glob.glob(opj(path, version, '*.py'))
                 for version in os.listdir(path)
-                if os.path.isdir(opj(path, version))
+                if _verify_upgrade_version(path, version)
             }
 
         for pkg in self.graph:
@@ -109,8 +151,10 @@ class MigrationManager(object):
             return
 
         def convert_version(version):
-            if version.count('.') >= 2:
-                return version  # the version number already contains the server version
+            if version == "0.0.0":
+                return version
+            if version.count(".") > 2:
+                return version  # the version number already contains the server version, see VERSION_RE for details
             return "%s.%s" % (release.major_version, version)
 
         def _get_migration_versions(pkg, stage):