--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -7,7 +7,7 @@ prune tests/*.err
 include *.txt
 include templates/map templates/map-*[a-z0-9]
 include templates/*.tmpl
-include doc/README doc/*.txt doc/Makefile
+include doc/README doc/Makefile doc/*.txt doc/*.html doc/*.[0-9]
 recursive-include contrib *
 include README
 include CONTRIBUTORS

new file mode 100644
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,23 @@
+# This Makefile is only used by developers.
+PYTHON=python
+
+all:
+	@echo "Read the file README for install instructions."
+
+clean:
+	-$(PYTHON) setup.py clean --all # ignore errors of this command
+	find . -name '*.py[co]' -exec rm -f '{}' ';'
+	make -C doc clean
+
+dist:	tests doc
+	TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py sdist --force-manifest
+
+tests:
+	cd tests && ./run-tests
+
+doc:
+	make -C doc
+
+
+.PHONY: all clean dist tests doc
+

--- a/doc/Makefile
+++ b/doc/Makefile
@@ -2,7 +2,7 @@ SOURCES=$(wildcard *.[0-9].txt)
 MAN=$(SOURCES:%.txt=%)
 HTML=$(SOURCES:%.txt=%.html)
 
-all: man
+all: man html
 
 man: $(MAN)
 

--- a/hgeditor
+++ b/hgeditor
@@ -51,7 +51,11 @@ fi
 grep -vE '^(HG: manifest hash .*)?$' "$1" >> "$HGTMP/msg"
 
 CHECKSUM=`md5sum "$HGTMP/msg"`
-$EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?
+if [ -s "$HGTMP/diff" ]; then
+    $EDITOR "$HGTMP/msg" "$HGTMP/diff" || exit $?
+else
+    $EDITOR "$HGTMP/msg" || exit $?
+fi
 echo "$CHECKSUM" | md5sum -c >/dev/null 2>&1 && exit 13
 
 if [ "$SIGN" == "1" ]; then