You are a helpful software engineer assistant. ## Tools You have access to the following tools: ### bash Description: Run commands in a bash shell * When invoking this tool, the contents of the "command" parameter does NOT need to be XML-escaped. * You don't have access to the internet via this tool. * You do have access to a mirror of common linux and python packages via apt and pip. * State is persistent across command calls and discussions with the user. * To inspect a particular line range of a file, e.g. lines 10-25, try 'sed -n 10,25p /path/to/the/file'. * Please avoid commands that may produce a very large amount of output. * Please run long lived commands in the background, e.g. 'sleep 10 &' or start a server in the background. Parameters: {"title": "BashInput", "type": "object", "properties": {"command": {"title": "Command", "description": "The bash command to run. Relative path is preferred in the command.", "type": "string"}}, "required": ["command"], "additionalProperties": false} ### str_replace_editor Description: Custom editing tool for viewing, creating and editing files * State is persistent across command calls and discussions with the user * If `path` is a file, `view` displays the result of applying `cat -n`. If `path` is a directory, `view` lists non-hidden files and directories up to 2 levels deep * The `create` command cannot be used if the specified `path` already exists as a file * If a `command` generates a long output, it will be truncated and marked with `<response clipped>` Notes for using the `str_replace` command: * The `old_str` parameter should match EXACTLY one or more consecutive lines from the original file. Be mindful of whitespaces! * If the `old_str` parameter is not unique in the file, the replacement will not be performed. Make sure to include enough context in `old_str` to make it unique * The `new_str` parameter should contain the edited lines that should replace the `old_str` Parameters: {"title": "SweEditorInput", "type": "object", "properties": {"command": {"title": "Command", "description": "The commands to run. Allowed options are: `view`, `create`, `str_replace`, `insert`.", "enum": ["view", "create", "str_replace", "insert"], "type": "string"}, "path": {"title": "Path", "description": "Absolute path to file or directory, e.g. `/repo/file.py` or `/repo`.", "type": "string"}, "file_text": {"title": "File Text", "description": "Required parameter of `create` command, with the content of the file to be created.", "type": "string"}, "insert_line": {"title": "Insert Line", "description": "Required parameter of `insert` command. The `new_str` will be inserted AFTER the line `insert_line` of `path`.", "type": "integer"}, "new_str": {"title": "New Str", "description": "Optional parameter of `str_replace` command containing the new string (if not given, no string will be added). Required parameter of `insert` command containing the string to insert.", "type": "string"}, "old_str": {"title": "Old Str", "description": "Required parameter of `str_replace` command containing the string in `path` to replace.", "type": "string"}, "view_range": {"title": "View Range", "description": "Optional parameter of `view` command when `path` points to a file. If none is given, the full file is shown. If provided, the file will be shown in the indicated line number range, e.g. [11, 12] will show lines 11 and 12. Indexing at 1 to start. Setting `[start_line, -1]` shows all lines from `start_line` to the end of the file.", "type": "array", "items": {"type": "integer"}}}, "required": ["command", "path"], "additionalProperties": false} IMPORTANT: ALWAYS adhere to this exact format for tool use: <｜tool▁calls▁begin｜><｜tool▁call▁begin｜>tool_call_name<｜tool▁sep｜>tool_call_arguments<｜tool▁call▁end｜>{additional_tool_calls}<｜tool▁calls▁end｜> Where: - `tool_call_name` must be an exact match to one of the available tools - `tool_call_arguments` must be valid JSON that strictly follows the tool's Parameters Schema - For multiple tool calls, chain them directly without separators or spaces<｜User｜><uploaded_files> /testbed </uploaded_files> I've uploaded a code repository in the directory /testbed (not in /tmp/inputs). Consider the following PR description: <pr_description> Bug in posix implementation of django/core/files/locks.py Description The posix version of locks (the version which supports import fcntl) has a bug. The code attempts to return True to indicate success or failure acquiring a lock, but instead it always returns False. The reason is that cpython fcntl module returns None if successful, and raises an OSError to indicate failure (see https://docs.python.org/3/library/fcntl.html#fcntl.flock). Anyone interested in using the non-blocking (i.e. locks.LOCKS_NB) requires a valid return value to know if they have successfully acquired the lock. I believe the correct implementation should be the following: diff --git a/django/core/files/locks.py b/django/core/files/locks.py index c46b00b905..4938347ea7 100644 --- a/django/core/files/locks.py +++ b/django/core/files/locks.py @@ -107,9 +107,15 @@ else: return True else: def lock(f, flags): - ret = fcntl.flock(_fd(f), flags) - return ret == 0 + try: + fcntl.flock(_fd(f), flags) + return True + except OSError: + return False def unlock(f): - ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) - return ret == 0 + try: + fcntl.flock(_fd(f), fcntl.LOCK_UN) + return True + except OSError: + return False </pr_description> Can you help me implement the necessary changes to the repository so that the requirements specified in the <pr_description> are met? I've already taken care of all changes to any of the test files described in the <pr_description>. This means you DON'T have to modify the testing logic or any of the tests in any way! Your task is to make the minimal changes to non-tests files in the /testbed directory to ensure the <pr_description> is satisfied. You are only allowed to call **ONE** function each time!<｜Assistant｜></think>I'll help you implement the necessary changes to fix the bug in the posix implementation of `django/core/files/locks.py`. Let me start by examining the current state of the file.<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "view", "path": "/testbed/django/core/files/locks.py"}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 116 lines): 1 """ 2 Portable file locking utilities. 3 4 Based partially on an example by Jonathan Feignberg in the Python 5 Cookbook [1] (licensed under the Python Software License) and a ctypes port by 6 Anatoly Techtonik for Roundup [2] (license [3]). 7 8 [1] http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65203 9 [2] https://sourceforge.net/p/roundup/code/ci/default/tree/roundup/backends/portalocker.py 10 [3] https://sourceforge.net/p/roundup/code/ci/default/tree/COPYING.txt 11 12 Example Usage:: 13 14 >>> from django.core.files import locks 15 >>> with open('./file', 'wb') as f: 16 ... locks.lock(f, locks.LOCK_EX) 17 ... f.write('Django') 18 """ 19 import os 20 21 __all__ = ('LOCK_EX', 'LOCK_SH', 'LOCK_NB', 'lock', 'unlock') 22 23 24 def _fd(f): 25 """Get a filedescriptor from something which could be a file or an fd.""" 26 return f.fileno() if hasattr(f, 'fileno') else f 27 28 29 if os.name == 'nt': 30 import msvcrt 31 from ctypes import ( 32 POINTER, Structure, Union, byref, c_int64, c_ulong, c_void_p, sizeof, 33 windll, 34 ) 35 from ctypes.wintypes import BOOL, DWORD, HANDLE 36 37 LOCK_SH = 0 # the default 38 LOCK_NB = 0x1 # LOCKFILE_FAIL_IMMEDIATELY 39 LOCK_EX = 0x2 # LOCKFILE_EXCLUSIVE_LOCK 40 41 # --- Adapted from the pyserial project --- 42 # detect size of ULONG_PTR 43 if sizeof(c_ulong) != sizeof(c_void_p): 44 ULONG_PTR = c_int64 45 else: 46 ULONG_PTR = c_ulong 47 PVOID = c_void_p 48 49 # --- Union inside Structure by stackoverflow:3480240 --- 50 class _OFFSET(Structure): 51 _fields_ = [ 52 ('Offset', DWORD), 53 ('OffsetHigh', DWORD)] 54 55 class _OFFSET_UNION(Union): 56 _anonymous_ = ['_offset'] 57 _fields_ = [ 58 ('_offset', _OFFSET), 59 ('Pointer', PVOID)] 60 61 class OVERLAPPED(Structure): 62 _anonymous_ = ['_offset_union'] 63 _fields_ = [ 64 ('Internal', ULONG_PTR), 65 ('InternalHigh', ULONG_PTR), 66 ('_offset_union', _OFFSET_UNION), 67 ('hEvent', HANDLE)] 68 69 LPOVERLAPPED = POINTER(OVERLAPPED) 70 71 # --- Define function prototypes for extra safety --- 72 LockFileEx = windll.kernel32.LockFileEx 73 LockFileEx.restype = BOOL 74 LockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, DWORD, LPOVERLAPPED] 75 UnlockFileEx = windll.kernel32.UnlockFileEx 76 UnlockFileEx.restype = BOOL 77 UnlockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, LPOVERLAPPED] 78 79 def lock(f, flags): 80 hfile = msvcrt.get_osfhandle(_fd(f)) 81 overlapped = OVERLAPPED() 82 ret = LockFileEx(hfile, flags, 0, 0, 0xFFFF0000, byref(overlapped)) 83 return bool(ret) 84 85 def unlock(f): 86 hfile = msvcrt.get_osfhandle(_fd(f)) 87 overlapped = OVERLAPPED() 88 ret = UnlockFileEx(hfile, 0, 0, 0xFFFF0000, byref(overlapped)) 89 return bool(ret) 90 else: 91 try: 92 import fcntl 93 LOCK_SH = fcntl.LOCK_SH # shared lock 94 LOCK_NB = fcntl.LOCK_NB # non-blocking 95 LOCK_EX = fcntl.LOCK_EX 96 except (ImportError, AttributeError): 97 # File locking is not supported. 98 LOCK_EX = LOCK_SH = LOCK_NB = 0 99 100 # Dummy functions that don't do anything. 101 def lock(f, flags): 102 # File is not locked 103 return False 104 105 def unlock(f): 106 # File is unlocked 107 return True 108 else: 109 def lock(f, flags): 110 ret = fcntl.flock(_fd(f), flags) 111 return ret == 0 112 113 def unlock(f): 114 ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) 115 return ret == 0 116 <｜tool▁output▁end｜>Now I can see the issue. Looking at the current implementation in lines 109-115, the code is trying to compare the return value of `fcntl.flock()` with 0, but according to the PR description, `fcntl.flock()` returns `None` on success and raises an `OSError` on failure. This means the current implementation will always return `False` because `None == 0` is `False`. Let me examine the specific lines that need to be changed:<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [109,116]}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 116 lines) with view_range=[109, 116]: 109 def lock(f, flags): 110 ret = fcntl.flock(_fd(f), flags) 111 return ret == 0 112 113 def unlock(f): 114 ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) 115 return ret == 0 116 <｜tool▁output▁end｜>Now I'll implement the fix as described in the PR description. The fix should wrap the `fcntl.flock()` calls in try-except blocks, returning `True` on success and `False` on `OSError`:<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "str_replace", "path": "/testbed/django/core/files/locks.py", "old_str": " def lock(f, flags):\n ret = fcntl.flock(_fd(f), flags)\n return ret == 0\n\n def unlock(f):\n ret = fcntl.flock(_fd(f), fcntl.LOCK_UN)\n return ret == 0", "new_str": " def lock(f, flags):\n try:\n fcntl.flock(_fd(f), flags)\n return True\n except OSError:\n return False\n\n def unlock(f):\n try:\n fcntl.flock(_fd(f), fcntl.LOCK_UN)\n return True\n except OSError:\n return False"}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>The file /testbed/django/core/files/locks.py has been edited successfully.<｜tool▁output▁end｜>Let me verify the changes by viewing the modified section:<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [109,116]}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[109, 116]: 109 def lock(f, flags): 110 try: 111 fcntl.flock(_fd(f), flags) 112 return True 113 except OSError: 114 return False 115 116 def unlock(f): <｜tool▁output▁end｜><｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [116,122]}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[116, 122]: 116 def unlock(f): 117 try: 118 fcntl.flock(_fd(f), fcntl.LOCK_UN) 119 return True 120 except OSError: 121 return False 122 <｜tool▁output▁end｜>Perfect! The changes have been successfully implemented. Let me verify the complete file structure to ensure everything looks correct:<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>str_replace_editor<｜tool▁sep｜>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [90,122]}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[90, 122]: 90 else: 91 try: 92 import fcntl 93 LOCK_SH = fcntl.LOCK_SH # shared lock 94 LOCK_NB = fcntl.LOCK_NB # non-blocking 95 LOCK_EX = fcntl.LOCK_EX 96 except (ImportError, AttributeError): 97 # File locking is not supported. 98 LOCK_EX = LOCK_SH = LOCK_NB = 0 99 100 # Dummy functions that don't do anything. 101 def lock(f, flags): 102 # File is not locked 103 return False 104 105 def unlock(f): 106 # File is unlocked 107 return True 108 else: 109 def lock(f, flags): 110 try: 111 fcntl.flock(_fd(f), flags) 112 return True 113 except OSError: 114 return False 115 116 def unlock(f): 117 try: 118 fcntl.flock(_fd(f), fcntl.LOCK_UN) 119 return True 120 except OSError: 121 return False 122 <｜tool▁output▁end｜>Excellent! The changes have been successfully implemented. Let me run a quick test to make sure the file is syntactically correct:<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>bash<｜tool▁sep｜>{"command": "cd /testbed && python -m py_compile django/core/files/locks.py"}<｜tool▁call▁end｜><｜tool▁calls▁end｜><｜end▁of▁sentence｜><｜tool▁output▁begin｜><｜tool▁output▁end｜>Great! The file compiles without any syntax errors. ## Summary I have successfully implemented the fix for the bug in the posix implementation of `django/core/files/locks.py`. The changes made are: 1. **Modified the `lock()` function** (lines 109-114): Wrapped the `fcntl.flock()` call in a try-except block that returns `True` on success and `False` when an `OSError` is raised. 2. **Modified the `unlock()` function** (lines 116-121): Similarly wrapped the `fcntl.flock()` call in a try-except block that returns `True` on success and `False` when an `OSError` is raised. The fix addresses the core issue described in the PR: - The original code incorrectly compared the return value of `fcntl.flock()` with 0, but `fcntl.flock()` returns `None` on success and raises an `OSError` on failure - This meant the functions always returned `False` (`None == 0` is `False`) - The new implementation properly handles the success/failure cases by using try-except blocks - This is particularly important for non-blocking locks (`LOCK_NB`) where callers need to know if the lock was successfully acquired The changes are minimal and focused, exactly matching the suggested fix in the PR description.<｜end▁of▁sentence｜>