Mercurial > hg-stable
view hgeditor @ 31485:9335dc6b2a9c
pager: avoid shell=True on subprocess.Popen for better errors (issue5491)
man(1) behaves as poorly as Mercurial without this change. This cribs
from git's run-command[0], which has a list of characters that imply a
string that needs to be run using 'sh -c'. If none of those characters
are present in the command string, we can use shell=False mode on
subprocess and get significantly better error messages (see the test)
when the pager process is invalid. With a complicated pager command
(that contains one of the unsafe characters), we behave as we do today
(which is no worse than git manages.)
I briefly tried tapdancing in a thread to catch early pager exits, but
it's just too perilous: you get races between fd duping operations and
a bad pager exiting, and it's too hard to differentiate between a
slow-bad-pager result and a fast-human-quit-pager-early result.
I've observed some weird variation in exit code handling in the "bad
experience" case in test-pager.t: on my Mac hg predictably exits
nonzero, but on Linux hg always exits zero in that case. For now,
we'll work around it with || true. :(
0: https://github.com/git/git/blob/cddbda4bc87b9d2c985b6749b1cf026b15e2d3e7/run-command.c#L201
author | Augie Fackler <augie@google.com> |
---|---|
date | Wed, 15 Mar 2017 20:33:47 -0400 |
parents | 1aee2ab0f902 |
children |
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#!/bin/sh # # This is an example of using HGEDITOR to create of diff to review the # changes while committing. # If you want to pass your favourite editor some other parameters # only for Mercurial, modify this: case "${EDITOR}" in "") EDITOR="vi" ;; emacs) EDITOR="$EDITOR -nw" ;; gvim|vim) EDITOR="$EDITOR -f -o" ;; esac HGTMP="" cleanup_exit() { rm -rf "$HGTMP" } # Remove temporary files even if we get interrupted trap "cleanup_exit" 0 # normal exit trap "exit 255" HUP INT QUIT ABRT TERM HGTMP=$(mktemp -d ${TMPDIR-/tmp}/hgeditor.XXXXXX) [ x$HGTMP != x -a -d $HGTMP ] || { echo "Could not create temporary directory! Exiting." 1>&2 exit 1 } ( grep '^HG: changed' "$1" | cut -b 13- | while read changed; do "$HG" diff "$changed" >> "$HGTMP/diff" done ) cat "$1" > "$HGTMP/msg" MD5=$(which md5sum 2>/dev/null) || \ MD5=$(which md5 2>/dev/null) [ -x "${MD5}" ] && CHECKSUM=`${MD5} "$HGTMP/msg"` if [ -s "$HGTMP/diff" ]; then $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $? else $EDITOR "$HGTMP/msg" || exit $? fi [ -x "${MD5}" ] && (echo "$CHECKSUM" | ${MD5} -c >/dev/null 2>&1 && exit 13) mv "$HGTMP/msg" "$1" exit $?