EmptyGlobalAssignment: ignore empty KEYWORDS

Resolves: #695
Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

Author: arthurzam

src/pkgcheck/checks/codingstyle.py

@@ -634,6 +634,8 @@ class MetadataVarCheck(Check):
     # mapping between registered variables and verification methods
     known_variables = {}
 
+    empty_vars_whitelist = frozenset({"KEYWORDS"})
+
     @verify_vars("HOMEPAGE", "KEYWORDS")
     def _raw_text(self, var, node, value, pkg):
         matches = []
@@ -710,8 +712,11 @@ def feed(self, pkg):
             value_str = self.canonicalize_assign(pkg.node_str(value_node)) if value_node else ""
             if name in pkg.eapi.eclass_keys:
                 if not value_str:
-                    lineno, _ = node.start_point
-                    yield EmptyGlobalAssignment(line=pkg.node_str(node), lineno=lineno + 1, pkg=pkg)
+                    if name not in self.empty_vars_whitelist:
+                        lineno, _ = node.start_point
+                        yield EmptyGlobalAssignment(
+                            line=pkg.node_str(node), lineno=lineno + 1, pkg=pkg
+                        )
                 elif pkg.node_str(value_node.prev_sibling) == "=":
                     for var_node, _ in bash.var_query.captures(value_node):
                         if (

testdata/data/repos/standalone/MetadataVarCheck/EmptyGlobalAssignment/expected.json

@@ -1,3 +1,2 @@
 {"__class__": "EmptyGlobalAssignment", "category": "DescriptionCheck", "package": "BadDescription", "version": "1", "line": "DESCRIPTION=\"\"", "lineno": 1}
-{"__class__": "EmptyGlobalAssignment", "category": "MetadataVarCheck", "package": "MultipleKeywordsLines", "version": "0", "line": "KEYWORDS=\"\"", "lineno": 8}
 {"__class__": "EmptyGlobalAssignment", "category": "MetadataVarCheck", "package": "ReferenceInMetadataVar", "version": "3", "line": "LICENSE=\"\"", "lineno": 4}