Fix other "cannot use name as import target" cases

Author: brianschubert

Grammar/python.gram

@@ -1434,13 +1434,13 @@ invalid_import:
 invalid_dotted_as_name:
     | a=dotted_name b=['as' NAME] c=dotted_name ('as' | ',' | ')' | ';' | NEWLINE) {
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(b ? (expr_ty) b : a, c, "expected comma between import clauses") }
-    | dotted_name 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
+    | dotted_name 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression (',' | ')' | ';' | NEWLINE) {
         RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
             "cannot use %s as import target", _PyPegen_get_expr_name(a)) }
 invalid_import_from_as_name:
     | [NAME 'as'] a=NAME b=NAME ('as' | ',' | ')' | ';' | NEWLINE) {
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected comma between import clauses") }
-    | NAME 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
+    | NAME 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression (',' | ')' | ';' | NEWLINE) {
         RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
             "cannot use %s as import target", _PyPegen_get_expr_name(a)) }
 

Lib/test/test_syntax.py

@@ -2206,6 +2206,25 @@
 Traceback (most recent call last):
 SyntaxError: cannot assign to None
 
+# Check that we don't raise a "cannot use name as import target" error
+# when there's a syntax error after the import target.
+
+>>> import a as b(-)
+Traceback (most recent call last):
+SyntaxError: invalid syntax
+
+>>> import a as b None
+Traceback (most recent call last):
+SyntaxError: invalid syntax
+
+>>> import a as b as c
+Traceback (most recent call last):
+SyntaxError: invalid syntax
+
+>>> from x import a as b None
+Traceback (most recent call last):
+SyntaxError: invalid syntax
+
 # Check that we dont raise the "trailing comma" error if there is more
 # input to the left of the valid part that we parsed.