fix f-string syntax error in code generation

CHANGES.rst

@@ -8,6 +8,9 @@ Unreleased
 -   The sandboxed environment handles indirect calls to ``str.format``, such as
     by passing a stored reference to a filter that calls its argument.
     :ghsa:`q2x7-8rv6-6q7h`
+-   Escape template name before formatting it into error messages, to avoid
+    issues with names that contain f-string syntax.
+    :issue:`1792`, :ghsa:`gmj6-6f8f-6699`
 -   Sandbox does not allow ``clear`` and ``pop`` on known mutable sequence
     types. :issue:`2032`
 -   Calling sync ``render`` for an async template uses ``asyncio.run``.

src/jinja2/compiler.py

@@ -1142,12 +1142,12 @@ def visit_FromImport(self, node: nodes.FromImport, frame: Frame) -> None:
             self.writeline(f"if {frame.symbols.ref(alias)} is missing:")
             self.indent()
             message = (
-                "the template {included_template.__name__!r}"
-                f" (imported on {self.position(node)})"
-                f" does not export the requested name {name!r}"
+                'f"the template {included_template.__name__!r}" + '
+                f'"(imported on {self.position(node)})" + '
+                f'"does not export the requested name {name!r}"'
             )
             self.writeline(
-                f"{frame.symbols.ref(alias)} = undefined(f{message!r}, name={name!r})"
+                f"{frame.symbols.ref(alias)} = undefined({message}, name={name!r})"
             )
             self.outdent()
             if frame.toplevel:

tests/test_compile.py

@@ -87,3 +87,15 @@ def test_block_set_vars_unpacking_deterministic(tmp_path):
         content,
     )[:10]
     assert found == expect
+
+
+def test_import_as_with_curly_braces_in_template_name():
+    env = Environment(
+        loader=DictLoader(
+            {
+                "template_with_{}": "{% import 'macro' as m %}",
+                "macro": "{% macro m() %}{% endmacro %}",
+            }
+        )
+    )
+    env.get_template("template_with_{}")