##// END OF EJS Templates
posix: always seek to EOF when opening a file in append mode...
posix: always seek to EOF when opening a file in append mode Python 3 already does this, so skip it there. Consider the program: #include <stdio.h> int main() { FILE *f = fopen("narf", "w"); fprintf(f, "narf\n"); fclose(f); f = fopen("narf", "a"); printf("%ld\n", ftell(f)); fprintf(f, "troz\n"); printf("%ld\n", ftell(f)); return 0; } on macOS, FreeBSD, and Linux with glibc, this program prints 5 10 but on musl libc (Alpine Linux and probably others) this prints 0 10 By my reading of https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html this is technically correct, specifically: > Opening a file with append mode (a as the first character in the > mode argument) shall cause all subsequent writes to the file to be > forced to the then current end-of-file, regardless of intervening > calls to fseek(). in other words, the file position doesn't really matter in append-mode files, and we can't depend on it being at all meaningful unless we perform a seek() before tell() after open(..., 'a'). Experimentally after a .write() we can do a .tell() and it'll always be reasonable, but I'm unclear from reading the specification if that's a smart thing to rely on. This matches what we do on Windows and what Python 3 does for free, so let's just be consistent. Thanks to Yuya for the idea.

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hg-test-mode.el
97 lines | 3.6 KiB | text/x-common-lisp | EmacsLispLexer
;; hg-test-mode.el - Major mode for editing Mercurial tests
;;
;; Copyright 2014 Matt Mackall <mpm@selenic.com>
;; "I have no idea what I'm doing"
;;
;; This software may be used and distributed according to the terms of the
;; GNU General Public License version 2 or any later version.
;;
;; To enable, add something like the following to your .emacs:
;;
;; (if (file-exists-p "~/hg/contrib/hg-test-mode.el")
;; (load "~/hg/contrib/hg-test-mode.el"))
(defvar hg-test-mode-hook nil)
(defvar hg-test-mode-map
(let ((map (make-keymap)))
(define-key map "\C-j" 'newline-and-indent)
map)
"Keymap for hg test major mode")
(add-to-list 'auto-mode-alist '("\\.t\\'" . hg-test-mode))
(defconst hg-test-font-lock-keywords-1
(list
'("^ \\(\\$\\|>>>\\) " 1 font-lock-builtin-face)
'("^ \\(>\\|\\.\\.\\.\\) " 1 font-lock-constant-face)
'("^ \\([[][0-9]+[]]\\)$" 1 font-lock-warning-face)
'("^ \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)*\\)$" 1 font-lock-string-face)
'("\\$?\\(HG\\|TEST\\)\\w+=?" . font-lock-variable-name-face)
'("^ \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)+\\)$" 2 font-lock-type-face)
'("^#.*" . font-lock-preprocessor-face)
'("^\\([^ ].*\\)$" 1 font-lock-comment-face)
)
"Minimal highlighting expressions for hg-test mode")
(defvar hg-test-font-lock-keywords hg-test-font-lock-keywords-1
"Default highlighting expressions for hg-test mode")
(defvar hg-test-mode-syntax-table
(let ((st (make-syntax-table)))
(modify-syntax-entry ?\" "w" st) ;; disable standard quoting
st)
"Syntax table for hg-test mode")
(defun hg-test-mode ()
(interactive)
(kill-all-local-variables)
(use-local-map hg-test-mode-map)
(set-syntax-table hg-test-mode-syntax-table)
(set (make-local-variable 'font-lock-defaults) '(hg-test-font-lock-keywords))
(setq major-mode 'hg-test-mode)
(setq mode-name "hg-test")
(run-hooks 'hg-test-mode-hook))
(with-eval-after-load "compile"
;; Link to Python sources in tracebacks in .t failures.
(add-to-list 'compilation-error-regexp-alist-alist
'(hg-test-output-python-tb
"^\\+ +File ['\"]\\([^'\"]+\\)['\"], line \\([0-9]+\\)," 1 2))
(add-to-list 'compilation-error-regexp-alist 'hg-test-output-python-tb)
;; Link to source files in test-check-code.t violations.
(add-to-list 'compilation-error-regexp-alist-alist
'(hg-test-check-code-output
"\\+ \\([^:\n]+\\):\\([0-9]+\\):$" 1 2))
(add-to-list 'compilation-error-regexp-alist 'hg-test-check-code-output))
(defun hg-test-mode--test-one-error-line-regexp (test)
(erase-buffer)
(setq compilation-locs (make-hash-table))
(insert (car test))
(compilation-parse-errors (point-min) (point-max))
(let ((msg (get-text-property 1 'compilation-message)))
(should msg)
(let ((loc (compilation--message->loc msg))
(line (nth 1 test))
(file (nth 2 test)))
(should (equal (compilation--loc->line loc) line))
(should (equal (caar (compilation--loc->file-struct loc)) file)))
msg))
(require 'ert)
(ert-deftest hg-test-mode--compilation-mode-support ()
"Test hg-specific compilation-mode regular expressions"
(require 'compile)
(with-temp-buffer
(font-lock-mode -1)
(mapc 'hg-test-mode--test-one-error-line-regexp
'(
("+ contrib/debugshell.py:37:" 37 "contrib/debugshell.py")
("+ File \"/tmp/hg/mercurial/commands.py\", line 3115, in help_"
3115 "/tmp/hg/mercurial/commands.py")
("+ File \"mercurial/dispatch.py\", line 225, in dispatch"
225 "mercurial/dispatch.py")))))
(provide 'hg-test-mode)