FEAT: Add --vt-keep-at-variants-in-shortnames option to preserve @default variants in test names

Add new command-line option --vt-keep-at-variants-in-shortnames to control
whether @-prefixed variants (like @default) are included in short test names
when using --vt-short-names-when-config.

Changes:
  - virttest/cartesian_config.py: Add keep_at_variants_in_shortnames parameter
    to Parser constructor and modify shortname generation logic
  - avocado_vt/plugins/vt.py: Add new CLI option --vt-keep-at-variants-in-shortnames
  - avocado_vt/plugins/vt_init.py: Register new setting for keep_at_variants_in_shortnames
  - avocado_vt/options.py: Pass new parameter to cartesian parser instantiation

Usage:
  avocado run xxxxx --vt-config myconfig.cfg --vt-short-names-when-config --vt-keep-at-variants-in-shortnames

  Without the flag: test.eim_off.q35 (excludes @default)
  With the flag: test.eim_off.default.q35 (includes @default)

Assisted-By: Claude Sonnet 4 <noreply@anthropic.com>
Signed-off-by: Houqi (Nick) Zuo <hzuo@redhat.com>

Author: nickzhq

avocado_vt/options.py

@@ -545,7 +545,11 @@ def _process_options(self):
                     % (vt_type_setting, vt_type, " ".join(SUPPORTED_TEST_TYPES))
                 )
 
-        self.cartesian_parser = cartesian_config.Parser(debug=False)
+        keep_at_variants = get_opt(self.config, "vt.keep_at_variants_in_shortnames", False)
+        self.cartesian_parser = cartesian_config.Parser(
+            debug=False,
+            keep_at_variants_in_shortnames=keep_at_variants
+        )
 
         if vt_config:
             cfg = os.path.abspath(vt_config)

avocado_vt/plugins/vt.py

@@ -68,6 +68,19 @@ def add_basic_vt_options(parser):
         help=help_msg,
     )
 
+    help_msg = (
+        "Keep @-prefixed variants (like @default) in short names. "
+        "Only works when --vt-short-names-when-config is also enabled."
+    )
+    add_option(
+        parser,
+        dest="vt.keep_at_variants_in_shortnames",
+        arg="--vt-keep-at-variants-in-shortnames",
+        action="store_true",
+        default=False,
+        help=help_msg,
+    )
+
     help_msg = "Choose test type (%s). Default: %%(default)s" % ", ".join(
         SUPPORTED_TEST_TYPES
     )

avocado_vt/plugins/vt_init.py

@@ -59,6 +59,18 @@ def initialize(self):
                 help_msg=help_msg,
             )
 
+            help_msg = (
+                "Keep @-prefixed variants (like @default) in short names. "
+                "Only works when short_names_when_config is also enabled."
+            )
+            settings.register_option(
+                section,
+                key="keep_at_variants_in_shortnames",
+                key_type=bool,
+                default=False,
+                help_msg=help_msg,
+            )
+
             help_msg = "Choose test type (%s). Default: %%(default)s" % ", ".join(
                 SUPPORTED_TEST_TYPES
             )

virttest/cartesian_config.py

@@ -1480,11 +1480,12 @@ def parse_filter(lexer, tokens):
 class Parser(object):
     # pylint: disable=W0102
 
-    def __init__(self, filename=None, defaults=False, expand_defaults=[], debug=False):
+    def __init__(self, filename=None, defaults=False, expand_defaults=[], debug=False, keep_at_variants_in_shortnames=False):
         self.node = Node()
         self.debug = debug
         self.defaults = defaults
         self.expand_defaults = [LIdentifier(x) for x in expand_defaults]
+        self.keep_at_variants_in_shortnames = keep_at_variants_in_shortnames
 
         self.filename = filename
         if self.filename:
@@ -1787,7 +1788,7 @@ def _parse(self, lexer, node=None, prev_indent=-1):
                             node3.default = True
                             already_default = True
 
-                        node3.append_to_shortname = not is_default
+                        node3.append_to_shortname = not is_default or self.keep_at_variants_in_shortnames
 
                         op = LUpdateFileMap()
                         op.set_operands(