hgeditor

head-revs: add a native implementation of the `stop_rev` parameter

This does not add too much complexity to the native code and help with
branchmap v3 performance.

Note that the final conversion of the heads from native-code to Python is still
too costly, especially in Rust. In addition the current caching around headrevs
is too simple and fragile. However these are an unrelated problem.


### benchmark.name                                 = hg.command.unbundle
  # bin-env-vars.hg.py-re2-module                  = default
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.resource-usage              = default
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
  # benchmark.variants.validate                    = default
  # benchmark.variants.verbosity                   = quiet

 ## data-env-vars.name     = netbeans-2018-08-01-zstd-sparse-revlog
  # bin-env-vars.hg.flavor = default
branch-v2:        0.233711  ~~~~~
branch-v3 before: 0.239857   (+2.63%, +0.01)
branch-v3 after:  0.239558   (+2.50%, +0.01)
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.235230  ~~~~~
branch-v3 before: 0.240972   (+2.44%, +0.01)
branch-v3 after:  0.239917   (+1.99%, +0.00)
 ## data-env-vars.name     = netbeans-2018-08-01-ds2-pnm
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.255586  ~~~~~
branch-v3 before: 0.268560   (+5.08%, +0.01)
branch-v3 after:  0.262261   (+2.61%, +0.01)

 ## data-env-vars.name     = mozilla-central-2024-03-22-zstd-sparse-revlog
  # bin-env-vars.hg.flavor = default
branch-v2:        0.339010  ~~~~~
branch-v3 before: 0.349389   (+3.06%, +0.01)
branch-v3 after:  0.348247   (+2.72%, +0.01)
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.346525  ~~~~~
branch-v3 before: 0.355661   (+2.64%, +0.01)
branch-v3 after:  0.350906   (+1.26%, +0.00)
 ## data-env-vars.name     = mozilla-central-2024-03-22-ds2-pnm
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.380202  ~~~~~
branch-v3 before: 0.408851   (+7.54%, +0.03)
branch-v3 after:  0.406511   (+6.92%, +0.03)


 ## data-env-vars.name     = mozilla-unified-2024-03-22-zstd-sparse-revlog
  # bin-env-vars.hg.flavor = default
branch-v2:        0.412165  ~~~~~
branch-v3 before: 0.427782   (+3.79%, +0.02)
branch-v3 after:  0.422595   (+2.53%, +0.01)
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.412397  ~~~~~
branch-v3 before: 0.422354   (+2.41%, +0.01)
branch-v3 after:  0.421079   (+2.11%, +0.01)
 ## data-env-vars.name     = mozilla-unified-2024-03-22-ds2-pnm
  # bin-env-vars.hg.flavor = rust
branch-v2:        0.429501  ~~~~~
branch-v3 before: 0.443197   (+3.19%, +0.01)
branch-v3 after:  0.449432   (+4.64%, +0.02)

 ## data-env-vars.name     = mozilla-try-2024-03-26-zstd-sparse-revlog
  # bin-env-vars.hg.flavor = default
branch-v2:        3.403171  ~~~~~
branch-v3 before: 3.819477  (+12.23%, +0.42)
branch-v3 after:  3.658482   (+7.50%, +0.26)
  # bin-env-vars.hg.flavor = rust
branch-v2:        3.454876  ~~~~~
branch-v3 before: 3.590284   (+3.92%, +0.14)
branch-v3 after:  3.545843   (+2.63%, +0.09)
 ## data-env-vars.name     = mozilla-try-2024-03-26-ds2-pnm
  # bin-env-vars.hg.flavor = rust
branch-v2:        3.465435  ~~~~~
branch-v3 before: 3.633278   (+4.84%, +0.17)
branch-v3 after:  3.556074   (+2.62%, +0.09)

#!/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 $?