build: persuade git-version-gen vMAJOR.MINOR tags just miss .0

Recent "v1.0" discovered this discrepancy propagated all around
and also this is not very compatible with the logic of commit 26d3911.

Treat missing "patch" component of the version as an implicit zero
to make such oddity go away.

Adjust spec file generation accordingly.

Makefile.am

@@ -60,16 +60,20 @@ $(SPEC): $(SPEC).in
 	@rm -f $@-t $@
 	@date="$(shell LC_ALL=C date "+%a %b %d %Y")" && \
 	if [ -f .tarball-version ]; then \
-		gitver="$(shell cat .tarball-version)" && \
+		ver="$(shell cat .tarball-version)" && \
+		gitver=`echo $$ver | sed \
+			-e 's|^\(v[0-9][0-9]*\.[0-9][0-9]*\)\([^.].*\)\?$$|\1.0\2|'` && \
 		rpmver=$$gitver && \
 		alphatag="" && \
 		dirty="" && \
 		numcomm="0"; \
 	else \
-		gitver="$(shell git describe --abbrev=4 --match='v*' --tags HEAD 2>/dev/null)" && \
+		ver="$(shell git describe --abbrev=4 --match='v*' --tags HEAD 2>/dev/null)" && \
+		gitver=`echo $$ver | sed \
+			-e 's|^\(v[0-9][0-9]*\.[0-9][0-9]*\)\([^.].*\)\?$$|\1.0\2|'` && \
 		rpmver=`echo $$gitver | sed -e "s/^v//" -e "s/-.*//g"` && \
 		alphatag=`echo $$gitver | sed -e "s/.*-//" -e "s/^g//"` && \
-		vtag=`echo $$gitver | sed -e "s/-.*//g"` && \
+		vtag=`echo $$ver | sed -e "s/-.*//g"` && \
 		numcomm=`git rev-list $$vtag..HEAD | wc -l` && \
 		git update-index --refresh > /dev/null 2>&1 || true && \
 		dirty=`git diff-index --name-only HEAD 2>/dev/null`; \

configure.ac

@@ -3,8 +3,10 @@
 
 AC_PREREQ([2.61])
 
+dnl inject zero as a "patch" component of the version if missing in tag
 AC_INIT([libqb],
-	m4_esyscmd([build-aux/git-version-gen .tarball-version]),
+	m4_esyscmd([build-aux/git-version-gen .tarball-version \
+		    's|^\(v[0-9][0-9]*\.[0-9][0-9]*\)\([^.].*\)\?$|\1.0\2|']),
 	[developers@clusterlabs.org])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_SRCDIR([lib/ringbuffer.c])