changegroup: don't send empty subdirectory manifest groups
When grafting/rebasing, it is common for multiple changesets to make
the same change to a subdirectory. When writing the revlog for the
directory, the revlog code already takes care of not writing the entry
again. In 0c2a088ffcc5 (changegroup: prune subdirectory dirlogs too,
2016-02-12), I added the corresponding code in changegroup (not
sending entries the client already has), but I forgot to avoid sending
the entire changegroup if no nodes remained in the pruned
set. Although that's harmless besides the wasted network traffic, the
receiving side was checking for it (copied from the changegroup code
for handling files). This resulted in the client crashing with:
abort: received dir revlog group is empty
Fix by simply not emitting a changegroup for the directory if there
were no changes is it. This matches how files are handled.
#!/usr/bin/env bash
# A simple script for opening merge conflicts in the editor.
# Use the following Mercurial settings to enable it.
#
# [ui]
# merge = editmerge
#
# [merge-tools]
# editmerge.args=$output
# editmerge.check=changed
# editmerge.premerge=keep
FILE="$1"
getlines() {
grep -n "^<<<<<<" "$FILE" | cut -f1 -d:
}
# editor preference loosely based on https://mercurial-scm.org/wiki/editor
# hg showconfig is at the bottom though, since it's slow to run (0.15 seconds)
ED="$HGEDITOR"
if [ "$ED" = "" ] ; then
ED="$VISUAL"
fi
if [ "$ED" = "" ] ; then
ED="$EDITOR"
fi
if [ "$ED" = "" ] ; then
ED="$(hg showconfig ui.editor)"
fi
if [ "$ED" = "" ] ; then
echo "merge failed - unable to find editor"
exit 1
fi
if [ "$ED" = "emacs" ] || [ "$ED" = "nano" ] || [ "$ED" = "vim" ] ; then
FIRSTLINE="$(getlines | head -n 1)"
PREVIOUSLINE=""
# open the editor to the first conflict until there are no more
# or the user stops editing the file
while [ ! "$FIRSTLINE" = "" ] && [ ! "$FIRSTLINE" = "$PREVIOUSLINE" ] ; do
$ED "+$FIRSTLINE" "$FILE"
PREVIOUSLINE="$FIRSTLINE"
FIRSTLINE="$(getlines | head -n 1)"
done
else
$ED "$FILE"
fi
# get the line numbers of the remaining conflicts
CONFLICTS="$(getlines | sed ':a;N;$!ba;s/\n/, /g')"
if [ ! "$CONFLICTS" = "" ] ; then
echo "merge failed - resolve the conflicts (line $CONFLICTS) then use 'hg resolve --mark'"
exit 1
fi
exit 0