Fixed false positive for arguments passed to class method without explicit 'self' (PY-6108)

python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java

@@ -235,7 +235,18 @@ public class PyCallExpressionHelper {
     boolean isByClass
   ) {
     int implicit_offset = 0;
-    if (isByInstance || isConstructorCall) implicit_offset += 1;
+    boolean firstIsArgsOrKwargs = false;
+    final PyParameter[] parameters = callable.getParameterList().getParameters();
+    if (parameters.length > 0) {
+      final PyParameter first = parameters[0];
+      final PyNamedParameter named = first.getAsNamed();
+      if (named != null && (named.isPositionalContainer() || named.isKeywordContainer())) {
+        firstIsArgsOrKwargs = true;
+      }
+    }
+    if (!firstIsArgsOrKwargs && (isByInstance || isConstructorCall)) {
+      implicit_offset += 1;
+    }
     PyFunction method = callable.asMethod();
     if (method == null) return implicit_offset;
 

python/testData/inspections/PyArgumentListInspection/args.py

@@ -10,6 +10,7 @@ def test_union_type():
     bar = (1,) if True else (1, 2)
     foo(*bar) #pass
 
+
 # PY-4890
 def test_old_style_iterable():
     class C:
@@ -22,4 +23,13 @@ def test_old_style_iterable():
         pass
     xs = C()
     foo(*xs) #pass
-    foo(*'bar') #pass
+    foo(*'bar') #pass
+
+
+# PY-6108
+def test_unexpected_args_without_self():
+    class C:
+        def sm(*args, **kwargs):
+            return args, kwargs
+    x = C()
+    x.sm(1, 2, 3) #pass