When we can't infer bare except handlers, skip ``try-except-raise``

Close #2853

4 files changed, 18 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index 0634fe387..f5a59538a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,10 @@ What's New in Pylint 2.4.0?
 
 Release date: TBA
 
+* When we can't infer bare except handlers, skip ``try-except-raise``
+
+  Close #2853
+
 * Handle more `unnecessary-lambda` cases when dealing with additional kwargs in wrapped calls
 
   Close #2845
diff --git a/pylint/checkers/exceptions.py b/pylint/checkers/exceptions.py
index 6521a5bd5..be4d7c9ac 100644
--- a/pylint/checkers/exceptions.py
+++ b/pylint/checkers/exceptions.py
@@ -28,6 +28,7 @@ import sys
 import typing
 
 import astroid
+from astroid.node_classes import NodeNG
 
 from pylint import checkers, interfaces
 from pylint.checkers import utils
@@ -405,7 +406,9 @@ class ExceptionsChecker(checkers.BaseChecker):
                 )
 
     def _check_try_except_raise(self, node):
-        def gather_exceptions_from_handler(handler):
+        def gather_exceptions_from_handler(
+            handler
+        ) -> typing.Optional[typing.List[NodeNG]]:
             exceptions = []
             if handler.type:
                 exceptions_in_handler = utils.safe_infer(handler.type)
@@ -417,6 +420,9 @@ class ExceptionsChecker(checkers.BaseChecker):
                     }
                 elif exceptions_in_handler:
                     exceptions = [exceptions_in_handler]
+                else:
+                    # Break when we cannot infer anything reliably.
+                    return None
             return exceptions
 
         bare_raise = False
@@ -429,9 +435,13 @@ class ExceptionsChecker(checkers.BaseChecker):
                 # also break early if bare except is followed by bare except.
 
                 excs_in_current_handler = gather_exceptions_from_handler(handler)
+
                 if not excs_in_current_handler:
                     bare_raise = False
                     break
+                if excs_in_bare_handler is None:
+                    # It can be `None` when the inference failed
+                    break
 
                 for exc_in_current_handler in excs_in_current_handler:
                     inferred_current = utils.safe_infer(exc_in_current_handler)
@@ -451,8 +461,9 @@ class ExceptionsChecker(checkers.BaseChecker):
                     bare_raise = True
                     handler_having_bare_raise = handler
                     excs_in_bare_handler = gather_exceptions_from_handler(handler)
-        if bare_raise:
-            self.add_message("try-except-raise", node=handler_having_bare_raise)
+        else:
+            if bare_raise:
+                self.add_message("try-except-raise", node=handler_having_bare_raise)
 
     @utils.check_messages("wrong-exception-operation")
     def visit_binop(self, node):
diff --git a/pylint/test/functional/try_except_raise.py b/pylint/test/functional/try_except_raise.py
index 2a9bed799..c78852b81 100644
--- a/pylint/test/functional/try_except_raise.py
+++ b/pylint/test/functional/try_except_raise.py
@@ -96,14 +96,6 @@ except (FileNotFoundError, PermissionError):  # [try-except-raise]
 except (OverflowError, ZeroDivisionError):
     print("a failure")
 
-
-try:
-    pass
-except invalid_name:  # [try-except-raise]
-    raise
-except TypeError:
-    pass
-
 try:
     pass
 except (FileNotFoundError, PermissionError):
@@ -117,4 +109,3 @@ except (FileNotFoundError, PermissionError):
     raise
 except (Exception,):
     print("a failure")
-    
\ No newline at end of file
diff --git a/pylint/test/functional/try_except_raise.txt b/pylint/test/functional/try_except_raise.txt
index ccf8f11c6..882fd4007 100644
--- a/pylint/test/functional/try_except_raise.txt
+++ b/pylint/test/functional/try_except_raise.txt
@@ -4,4 +4,3 @@ try-except-raise:53:ddd:The except handler raises immediately
 try-except-raise:67::The except handler raises immediately
 try-except-raise:72::The except handler raises immediately
 try-except-raise:94::The except handler raises immediately
-try-except-raise:102::The except handler raises immediately