Don't emit catching-non-exception when a tuple component has unknown bases

Close #1756

2 files changed, 14 insertions, 1 deletions

diff --git a/pylint/checkers/exceptions.py b/pylint/checkers/exceptions.py
index 0d8c05954..2130a99be 100644
--- a/pylint/checkers/exceptions.py
+++ b/pylint/checkers/exceptions.py
@@ -305,7 +305,8 @@ class ExceptionsChecker(checkers.BaseChecker):
             if any(node is astroid.YES for node in inferred):
                 # Don't emit if we don't know every component.
                 return
-            if all(node and utils.inherit_from_std_ex(node)
+            if all(node and (utils.inherit_from_std_ex(node) or
+                             not utils.has_known_bases(node))
                    for node in inferred):
                 return
 
diff --git a/pylint/test/functional/invalid_exceptions_caught.py b/pylint/test/functional/invalid_exceptions_caught.py
index 2d87239e6..2b1dbacd8 100644
--- a/pylint/test/functional/invalid_exceptions_caught.py
+++ b/pylint/test/functional/invalid_exceptions_caught.py
@@ -121,3 +121,15 @@ try:
     raise Second
 except Second:
     pass
+
+
+class SomeBase(UnknownError):
+    pass
+
+
+EXCEPTIONS = (SomeBase, ValueError)
+
+try:
+    raise ValueError
+except EXCEPTIONS:
+    pass