Allow semantic analyzer errors to be suppressed with # type: ignore

mypy/semanal.py

@@ -2357,7 +2357,9 @@ def __init__(self, modules: Dict[str, MypyFile], errors: Errors) -> None:
 
     def visit_file(self, file_node: MypyFile, fnam: str) -> None:
         self.errors.set_file(fnam)
+        self.errors.set_ignored_lines(file_node.ignored_lines)
         file_node.accept(self)
+        self.errors.set_ignored_lines(set())
 
     def visit_func_def(self, fdef: FuncDef) -> None:
         self.errors.push_function(fdef.name())

mypy/test/data/check-ignore.test

@@ -146,3 +146,26 @@ if 1:  # type: ignore
     # blah
     pass
 [out]
+
+[case testIgnoreTooManyTypeArguments]
+from typing import TypeVar, Generic
+T = TypeVar('T')
+U = TypeVar('U')
+
+class Base(Generic[T, U]):
+  pass
+
+class PartialBase(Base[T, int], Generic[T]):
+  pass
+
+class Child(PartialBase[str, int]):  # type: ignore
+  pass
+
+
+def foo(x: Base[str, int]) -> None: pass
+foo(Child())
+
+def bar(x: Base[str, str]) -> None: pass
+bar(Child())
+[out]
+main:19: error: Argument 1 to "bar" has incompatible type "Child"; expected Base[str, str]