--- a/.hgeditor	Thu Dec 22 13:40:29 2016 +0800
+++ b/.hgeditor	Thu Dec 22 13:41:34 2016 +0800
@@ -1,8 +1,4 @@
 #!/bin/sh
-#
-# This is an example of using HGEDITOR to create of diff to review the
-# changes while commiting.
-
 
 HGTMP=""
 cleanup_exit() {
@@ -19,13 +15,13 @@
     exit 1
 fi
 
-(
-    grep '^HG: \(changed\|added\|removed\)' "$1" | cut -d ' ' -f 3- | while read changed; do
-        "$HG" diff "$changed" >> "$HGTMP/diff"
-    done
-)
-
-cat "$1" > "$HGTMP/msg"
+LINE=$(fgrep 'HG: --- 8< ---' -nm1 "$1" | cut -d: -f1)
+if [ -n "$LINE" ]; then
+    head -n "$(( LINE - 1 ))" "$1" > "$HGTMP/msg"
+    tail -n +"$(( LINE + 1 ))" "$1" | sed -e 's/^HG: //g' > "$HGTMP/diff"
+else
+    cat "$1" > "$HGTMP/msg"
+fi
 
 MD5=$(which md5sum 2>/dev/null) || \
     MD5=$(which md5 2>/dev/null)

--- a/.hgrc	Thu Dec 22 13:40:29 2016 +0800
+++ b/.hgrc	Thu Dec 22 13:41:34 2016 +0800
@@ -43,3 +43,20 @@
 
 changeset.public = green
 changeset.secret = red
+
+[committemplate]
+changeset = {desc}\n\n
+    HG: Enter commit message.  Lines beginning with 'HG:' are removed.
+    HG: {extramsg}
+    HG: --
+    HG: user: {author}\n{ifeq(p2rev, "-1", "",
+   "HG: branch merge\n")
+   }HG: branch '{branch}'\n{if(activebookmark,
+   "HG: bookmark '{activebookmark}'\n")   }{subrepos %
+   "HG: subrepo {subrepo}\n"              }{file_adds %
+   "HG: added {file}\n"                   }{file_mods %
+   "HG: changed {file}\n"                 }{file_dels %
+   "HG: removed {file}\n"                 }{if(files, "",
+   "HG: no files changed\n")
+   }HG: --- 8< ---
+   {splitlines(diff()) % 'HG: {line}\n'}