From 65b6d5d7407636f2e434670c1cb332e0117dd22c Mon Sep 17 00:00:00 2001
From: Nick Drozd <nicholasdrozd@gmail.com>
Date: Sun, 22 Sep 2024 09:00:09 -0400
Subject: [PATCH] Check for empty format specs (#2574)

(cherry picked from commit a679550d3dc87edaa35b334771527cba5102a373)
---
 ChangeLog                     | 5 +++++
 astroid/nodes/node_classes.py | 3 +++
 tests/test_inference.py       | 8 ++++++++
 3 files changed, 16 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 1ad303a154..a53ed9e417 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -15,6 +15,11 @@ Release date: TBA
 
 
 
+* Fix a crash from inferring empty format specs.
+
+  Closes pylint-dev/pylint#9945
+
+
 What's New in astroid 3.3.3?
 ============================
 Release date: 2024-09-20
diff --git a/astroid/nodes/node_classes.py b/astroid/nodes/node_classes.py
index 1924c78eba..c326abbb3e 100644
--- a/astroid/nodes/node_classes.py
+++ b/astroid/nodes/node_classes.py
@@ -4779,6 +4779,9 @@ def _infer(
     def _infer_from_values(
         cls, nodes: list[NodeNG], context: InferenceContext | None = None, **kwargs: Any
     ) -> Generator[InferenceResult, None, InferenceErrorInfo | None]:
+        if not nodes:
+            yield
+            return
         if len(nodes) == 1:
             yield from nodes[0]._infer(context, **kwargs)
             return
diff --git a/tests/test_inference.py b/tests/test_inference.py
index 185ee0f650..daa5613565 100644
--- a/tests/test_inference.py
+++ b/tests/test_inference.py
@@ -7380,3 +7380,11 @@ def test_sys_argv_uninferable() -> None:
     sys_argv_value = list(a._infer())
     assert len(sys_argv_value) == 1
     assert sys_argv_value[0] is Uninferable
+
+
+def test_empty_format_spec() -> None:
+    """Regression test for https://github.com/pylint-dev/pylint/issues/9945."""
+    node = extract_node('f"{x:}"')
+    assert isinstance(node, nodes.JoinedStr)
+
+    assert list(node.infer()) == [util.Uninferable]