From 0348fe32b2f5c7d80789143f3e69ccfc6e7dd319 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sun, 20 Oct 2024 21:04:25 -0400
Subject: [PATCH] dont consume ampersands

Fixed long standing bug where the sequence ``<&`` would be misinterpreted
by the lexer.   It's not clear why the ampersand character was part of the
characters being consumed here and it may have been an inadvertent bit of
code from one of Mako's predecessor languages.

Fixes: #412
Change-Id: I41ba50da919a6c8b3557bdd2313aa545b51b2b9b
---
 doc/build/unreleased/412.rst |  8 ++++++++
 mako/lexer.py                |  2 +-
 test/test_lexer.py           | 11 +++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 doc/build/unreleased/412.rst

diff --git a/doc/build/unreleased/412.rst b/doc/build/unreleased/412.rst
new file mode 100644
index 00000000..3ee9bb62
--- /dev/null
+++ b/doc/build/unreleased/412.rst
@@ -0,0 +1,8 @@
+.. change::
+    :tags: bug, lexer
+    :tickets: 412
+
+    Fixed long standing bug where the sequence ``<&`` would be misinterpreted
+    by the lexer.   It's not clear why the ampersand character was part of the
+    characters being consumed here and it may have been an inadvertent bit of
+    code from one of Mako's predecessor languages.
diff --git a/mako/lexer.py b/mako/lexer.py
index 9d1f5f30..b4a76a45 100644
--- a/mako/lexer.py
+++ b/mako/lexer.py
@@ -375,7 +375,7 @@ def match_text(self):
                  |
                  (?=\${)      # an expression
                  |
-                 (?=</?[%&])  # a substitution or block or call start or end
+                 (?=</?%)  # a substitution or block or call start or end
                               # - don't consume
                  |
                  (\\\r?\n)    # an escaped newline  - throw away
diff --git a/test/test_lexer.py b/test/test_lexer.py
index d8029a17..05aaa1f0 100644
--- a/test/test_lexer.py
+++ b/test/test_lexer.py
@@ -827,6 +827,17 @@ def test_dict_expression_issue_400_regression(self):
             ),
         )
 
+    def test_ampersand_issue_412(self):
+        template = """
+property = <&node>;
+
+"""
+        nodes = Lexer(template).parse()
+        self._compare(
+            nodes,
+            TemplateNode({}, [Text("\nproperty = <&node>;\n\n", (1, 1))]),
+        )
+
     def _dont_test_dict_expression_issue_400(self):
         """test for issue #400"""
         template = """