checkpoint

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2026-10-08 03:10:26 +00:00 · 2026-03-16 01:33:47 -04:00 · 2026-03-16 01:33:47 -04:00 · 14666944d8
commit 14666944d8
parent 2e2625d66a
5 changed files with 154 additions and 21 deletions
--- a/checkpoint.json
+++ b/checkpoint.json
@ -1,13 +1,15 @@
 {
-  "timestamp": "2026-03-16T05:33:45.145949Z",
-  "current_node": "solve",
+  "timestamp": "2026-03-16T05:33:47.387394Z",
+  "current_node": "extract_patch",
  "completed_nodes": [
    "start",
    "setup",
-    "solve"
+    "solve",
+    "extract_patch"
  ],
  "node_retries": {
    "setup": 1,
+    "extract_patch": 1,
    "solve": 1,
    "start": 1
  },
@ -22,32 +24,22 @@
    "graph.rankdir": "LR",
    "graph.goal": "UsernameValidator allows trailing newline in usernames\nDescription\n\t\nASCIIUsernameValidator and UnicodeUsernameValidator use the regex \nr'^[\\w.@+-]+$'\nThe intent is to only allow alphanumeric characters as well as ., @, +, and -. However, a little known quirk of Python regexes is that $ will also match a trailing newline. Therefore, the user name validators will accept usernames which end with a newline. You can avoid this behavior by instead using \\A and \\Z to terminate regexes. For example, the validator regex could be changed to\nr'\\A[\\w.@+-]+\\Z'\nin order to reject usernames that end with a newline.\nI am not sure how to officially post a patch, but the required change is trivial - using the regex above in the two validators in contrib.auth.validators.\n",
    "internal.retry_count.solve": 1,
-    "internal.thread_id": "setup",
+    "internal.thread_id": "solve",
+    "thread.solve.current_node": "extract_patch",
    "internal.retry_count.start": 1,
-    "command.output": "fatal: destination path '.' already exists and is not an empty directory.\n",
-    "current.preamble": "Goal: UsernameValidator allows trailing newline in usernames\nDescription\n\t\nASCIIUsernameValidator and UnicodeUsernameValidator use the regex \nr'^[\\w.@+-]+$'\nThe intent is to only allow alphanumeric characters as well as ., @, +, and -. However, a little known quirk of Python regexes is that $ will also match a trailing newline. Therefore, the user name validators will accept usernames which end with a newline. You can avoid this behavior by instead using \\A and \\Z to terminate regexes. For example, the validator regex could be changed to\nr'\\A[\\w.@+-]+\\Z'\nin order to reject usernames that end with a newline.\nI am not sure how to officially post a patch, but the required change is trivial - using the regex above in the two validators in contrib.auth.validators.\n\n\n## Completed stages\n- **setup**: fail\n  - Script: `git clone https://github.com/django/django.git . && git checkout d26b2424437dabeeca94d7900b37d2df4410da0c && python -m pip install -e .`\n  - Stdout:\n    ```\n    fatal: destination path '.' already exists and is not an empty directory.\n    ```\n  - Stderr: (empty)\n\n## Context\n- failure_class: deterministic\n- failure_signature: setup|deterministic|script failed with exit code: <n> ## stdout fatal: destination path '.' already exists and is not an empty directory.\n",
+    "command.output": "",
+    "current.preamble": "Goal: UsernameValidator allows trailing newline in usernames\nDescription\n\t\nASCIIUsernameValidator and UnicodeUsernameValidator use the regex \nr'^[\\w.@+-]+$'\nThe intent is to only allow alphanumeric characters as well as ., @, +, and -. However, a little known quirk of Python regexes is that $ will also match a trailing newline. Therefore, the user name validators will accept usernames which end with a newline. You can avoid this behavior by instead using \\A and \\Z to terminate regexes. For example, the validator regex could be changed to\nr'\\A[\\w.@+-]+\\Z'\nin order to reject usernames that end with a newline.\nI am not sure how to officially post a patch, but the required change is trivial - using the regex above in the two validators in contrib.auth.validators.\n\n\n## Completed stages\n- **setup**: fail\n  - Script: `git clone https://github.com/django/django.git . && git checkout d26b2424437dabeeca94d7900b37d2df4410da0c && python -m pip install -e .`\n  - Stdout:\n    ```\n    fatal: destination path '.' already exists and is not an empty directory.\n    ```\n  - Stderr: (empty)\n- **solve**: success\n  - Model: claude-haiku-4-5, 15.5k tokens in / 5.7k out\n  - Files: /home/daytona/workspace/SOLUTION.md, /tmp/django-repo/django/contrib/auth/validators.py, /tmp/test_regex.py, /tmp/test_validators.py\n",
    "thread.start.current_node": "setup",
    "failure_class": "",
    "internal.retry_count.setup": 1,
    "last_response": "## Summary\n\nI've successfully fixed the GitHub issue **\"UsernameValidator allows trailing newline in usernames\"** in Django.\n\n### The Problem\nThe username validators used regex patterns with `^` and `",
    "thread.setup.current_node": "solve",
+    "internal.retry_count.extract_patch": 1,
    "last_stage": "solve",
-    "current_node": "solve"
+    "current_node": "extract_patch"
  },
  "logs": [],
  "node_outcomes": {
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-      "status": "fail",
-      "context_updates": {
-        "command.output": "fatal: destination path '.' already exists and is not an empty directory.\n",
-        "command.stderr": ""
-      },
-      "failure": {
-        "message": "Script failed with exit code: 128\n\n## stdout\nfatal: destination path '.' already exists and is not an empty directory.\n",
-        "failure_class": "deterministic"
-      },
-      "duration_ms": 48
-    },
    "solve": {
      "status": "success",
      "context_updates": {
@ -72,18 +64,40 @@
      ],
      "duration_ms": 71292
    },
+    "setup": {
+      "status": "fail",
+      "context_updates": {
+        "command.output": "fatal: destination path '.' already exists and is not an empty directory.\n",
+        "command.stderr": ""
+      },
+      "failure": {
+        "message": "Script failed with exit code: 128\n\n## stdout\nfatal: destination path '.' already exists and is not an empty directory.\n",
+        "failure_class": "deterministic"
+      },
+      "duration_ms": 48
+    },
+    "extract_patch": {
+      "status": "success",
+      "context_updates": {
+        "command.output": "",
+        "command.stderr": ""
+      },
+      "notes": "Script completed: git diff",
+      "duration_ms": 54
+    },
    "start": {
      "status": "success",
      "duration_ms": 0
    }
  },
-  "next_node_id": "extract_patch",
+  "next_node_id": "exit",
  "loop_failure_signatures": {
    "setup|deterministic|script failed with exit code: <n> ## stdout fatal: destination path '.' already exists and is not an empty directory.": 1
  },
  "node_visits": {
    "setup": 1,
+    "solve": 1,
    "start": 1,
-    "solve": 1
+    "extract_patch": 1
  }
 }
--- a/nodes/extract_patch/script_invocation.json
+++ b/nodes/extract_patch/script_invocation.json
@ -0,0 +1,5 @@
+{
+  "command": "git diff",
+  "language": "shell",
+  "timeout_ms": null
+}
--- a/nodes/extract_patch/script_timing.json
+++ b/nodes/extract_patch/script_timing.json
@ -0,0 +1,5 @@
+{
+  "duration_ms": 52,
+  "exit_code": 0,
+  "timed_out": false
+}
--- a/nodes/extract_patch/status.json
+++ b/nodes/extract_patch/status.json
@ -0,0 +1,6 @@
+{
+  "status": "success",
+  "notes": "Script completed: git diff",
+  "failure_reason": null,
+  "timestamp": "2026-03-16T05:33:47.386118+00:00"
+}
--- a/nodes/solve/diff.patch
+++ b/nodes/solve/diff.patch
@ -0,0 +1,103 @@
+diff --git a/SOLUTION.md b/SOLUTION.md
+new file mode 100644
+index 0000000..9d5bb32
+--- /dev/null
+++ b/SOLUTION.md
+@@ -0,0 +1,65 @@
+# Fix: UsernameValidator allows trailing newline in usernames
+
+## Problem
+The `ASCIIUsernameValidator` and `UnicodeUsernameValidator` classes in `django/contrib/auth/validators.py` used regex patterns with `^` and `$` anchors, which have a quirk in Python: `$` matches both the end of string AND before a trailing newline character.
+
+This caused the validators to incorrectly accept usernames ending with a newline (e.g., `"username\n"`).
+
+## Root Cause
+The original regex patterns were:
+```python
+regex = r'^[\w.@+-]+$'
+```
+
+The `$` anchor in Python regex matches:
+1. The absolute end of string
+2. **Also** before a trailing newline character (POSIX behavior)
+
+## Solution
+Changed the regex patterns to use `\A` and `\Z` anchors instead:
+```python
+regex = r'\A[\w.@+-]+\Z'
+```
+
+Where:
+- `\A` - matches only the absolute start of string (not after newlines)
+- `\Z` - matches only the absolute end of string (not before newlines)
+
+## Changes Made
+Modified two validator classes in `django/contrib/auth/validators.py`:
+
+1. **ASCIIUsernameValidator** (line 10):
+   - From: `regex = r'^[\w.@+-]+$'`
+   - To: `regex = r'\A[\w.@+-]+\Z'`
+
+2. **UnicodeUsernameValidator** (line 20):
+   - From: `regex = r'^[\w.@+-]+$'`
+   - To: `regex = r'\A[\w.@+-]+\Z'`
+
+## Testing
+Tested with both regexes to verify:
+
+### OLD regex behavior (`^[\w.@+-]+$`):
+```
+'validuser'        -> MATCH ✓ (correct)
+'user-name'        -> MATCH ✓ (correct)
+'validuser\n'      -> MATCH ✗ (BUG - should not match)
+'user-name\n'      -> MATCH ✗ (BUG - should not match)
+'user with space'  -> NO MATCH ✓ (correct)
+'user!invalid'     -> NO MATCH ✓ (correct)
+```
+
+### NEW regex behavior (`\A[\w.@+-]+\Z`):
+```
+'validuser'        -> MATCH ✓ (correct)
+'user-name'        -> MATCH ✓ (correct)
+'validuser\n'      -> NO MATCH ✓ (FIXED)
+'user-name\n'      -> NO MATCH ✓ (FIXED)
+'user with space'  -> NO MATCH ✓ (correct)
+'user!invalid'     -> NO MATCH ✓ (correct)
+```
+
+## Impact
+- **Security**: Prevents acceptance of usernames with trailing newlines, which could bypass validation in some contexts
+- **Correctness**: Makes the validators behave as intended, accepting only alphanumeric characters plus `.@+-_`
+- **Compatibility**: No breaking changes - all previously valid usernames remain valid; only invalid usernames (with trailing newlines) are now properly rejected
+diff --git a/validators.py b/validators.py
+new file mode 100644
+index 0000000..74e31f5
+--- /dev/null
+++ b/validators.py
+@@ -0,0 +1,25 @@
+import re
+
+from django.core import validators
+from django.utils.deconstruct import deconstructible
+from django.utils.translation import gettext_lazy as _
+
+
+@deconstructible
+class ASCIIUsernameValidator(validators.RegexValidator):
+    regex = r'\A[\w.@+-]+\Z'
+    message = _(
+        'Enter a valid username. This value may contain only English letters, '
+        'numbers, and @/./+/-/_ characters.'
+    )
+    flags = re.ASCII
+
+
+@deconstructible
+class UnicodeUsernameValidator(validators.RegexValidator):
+    regex = r'\A[\w.@+-]+\Z'
+    message = _(
+        'Enter a valid username. This value may contain only letters, '
+        'numbers, and @/./+/-/_ characters.'
+    )
+    flags = 0
+\ No newline at end of file