From 1d935ab47d15d2e9f26d2324403516bed5e94bb6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 2 Oct 2026 10:54:00 +0000
Subject: [PATCH 1/2] Initial plan


From 2358a9e74160dbbbb7428e43cb85aff549ab665d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 2 Oct 2026 10:55:56 +0000
Subject: [PATCH 2/2] Normalize invalid JSON Pointer assignment failures

Co-authored-by: stefankoegl <184196+stefankoegl@users.noreply.github.com>
---
 jsonpointer.py | 13 +++++++++----
 tests.py       | 22 ++++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/jsonpointer.py b/jsonpointer.py
index 7963703..0c1a1e0 100644
--- a/jsonpointer.py
+++ b/jsonpointer.py
@@ -209,10 +209,15 @@ def set(self, doc, value, inplace=True):
 
         (parent, part) = self.to_last(doc)
 
-        if isinstance(parent, Sequence) and part == '-':
-            parent.append(value)
-        else:
-            parent[part] = value
+        try:
+            if isinstance(parent, Sequence) and part == '-':
+                parent.append(value)
+            else:
+                parent[part] = value
+        except IndexError:
+            raise JsonPointerException("index '%s' is out of bounds" % (part,))
+        except (TypeError, AttributeError):
+            raise JsonPointerException("Cannot set token '%s' on type %s" % (part, type(parent)))
 
         return doc
 
diff --git a/tests.py b/tests.py
index 13c0561..981e2fa 100755
--- a/tests.py
+++ b/tests.py
@@ -271,6 +271,28 @@ def test_path(self):
 
 class SetTests(unittest.TestCase):
 
+    def test_invalid_assignment_target(self):
+        targets = ["abc", b"abc", (1, 2), 42, None]
+        for target in targets:
+            for token in ["0", "-"]:
+                for inplace in [True, False]:
+                    for doc, path in [(target, "/" + token),
+                                      ({"foo": target}, "/foo/" + token)]:
+                        with self.subTest(doc=doc, path=path, inplace=inplace):
+                            self.assertRaises(JsonPointerException, set_pointer,
+                                              doc, path, 42, inplace=inplace)
+
+    def test_assignment_out_of_bounds(self):
+        for target, token in [([], "0"), ([1, 2], "2"), ([1, 2], "5")]:
+            for inplace in [True, False]:
+                for doc, path in [(target, "/" + token),
+                                  ({"foo": target}, "/foo/" + token)]:
+                    original = copy.deepcopy(doc)
+                    with self.subTest(doc=doc, path=path, inplace=inplace):
+                        self.assertRaisesRegex(JsonPointerException, "out of bounds",
+                                               JsonPointer(path).set, doc, 42, inplace=inplace)
+                        self.assertEqual(doc, original)
+
     def test_set(self):
         doc = {
             "foo": ["bar", "baz"],