apply_patch in system prompt is inconsistent with the actual impl #2578
Description
What version of Codex is running?
master
Which model were you using?
gpt5
What platform is your computer?
linux
What steps can reproduce the bug?
in src/core/prompt.md:
## `apply_patch`
Your patch language is a stripped‑down, file‑oriented diff format designed to be easy to parse and safe to apply. You can think of it as a high‑level envelope:
**_ Begin Patch
[ one or more file sections ]
_** End Patch
Within that envelope, you get a sequence of file operations.
You MUST include a header to specify the action you are taking.
Each operation starts with one of three headers:
**_ Add File: <path> - create a new file. Every following line is a + line (the initial contents).
_** Delete File: <path> - remove an existing file. Nothing follows.
\*\*\* Update File: <path> - patch an existing file in place (optionally with a rename).
May be immediately followed by \*\*\* Move to: <new path> if you want to rename the file.
Then one or more “hunks”, each introduced by @@ (optionally followed by a hunk header).
Within a hunk each line starts with:
- for inserted text,
* for removed text, or
space ( ) for context.
At the end of a truncated hunk you can emit \*\*\* End of File.
Patch := Begin { FileOp } End
Begin := "**_ Begin Patch" NEWLINE
End := "_** End Patch" NEWLINE
FileOp := AddFile | DeleteFile | UpdateFile
AddFile := "**_ Add File: " path NEWLINE { "+" line NEWLINE }
DeleteFile := "_** Delete File: " path NEWLINE
UpdateFile := "**_ Update File: " path NEWLINE [ MoveTo ] { Hunk }
MoveTo := "_** Move to: " newPath NEWLINE
Hunk := "@@" [ header ] NEWLINE { HunkLine } [ "*** End of File" NEWLINE ]
HunkLine := (" " | "-" | "+") text NEWLINE
A full patch can combine several operations:
**_ Begin Patch
_** Add File: hello.txt
+Hello world
**_ Update File: src/app.py
_** Move to: src/main.py
@@ def greet():
-print("Hi")
+print("Hello, world!")
**_ Delete File: obsolete.txt
_** End PatchYou told llm to use **_ Begin Patch, _** End Patch, **_ Add File ...
But in apply-patch.rs, the parse want just ***
//! The official Lark grammar for the apply-patch format is:
//!
//! start: begin_patch hunk+ end_patch
//! begin_patch: "*** Begin Patch" LF
//! end_patch: "*** End Patch" LF?
//!
//! hunk: add_hunk | delete_hunk | update_hunk
//! add_hunk: "*** Add File: " filename LF add_line+
//! delete_hunk: "*** Delete File: " filename LF
//! update_hunk: "*** Update File: " filename LF change_move? change?
//! filename: /(.+)/
//! add_line: "+" /(.+)/ LF -> line
//!
//! change_move: "*** Move to: " filename LF
//! change: (change_context | change_line)+ eof_line?
//! change_context: ("@@" | "@@ " /(.+)/) LF
//! change_line: ("+" | "-" | " ") /(.+)/ LF
//! eof_line: "*** End of File" LF
//!
//! The parser below is a little more lenient than the explicit spec and allows for
//! leading/trailing whitespace around patch markers.
Which will confuse the llm
What is the expected behavior?
keep the prompt consistent with the parser logic
What do you see instead?
No response
Additional information
No response