Support alpha and beta pre-release markers.

For alpha or beta releases DIFFPY_VERSION is decreased by 500.
This ensures version number will be higher in actual release.

Author: pavoljuhas

site_scons/libdiffpybuildutils.py

@@ -23,10 +23,11 @@ def gitinfo():
     glog = proc.stdout.read()
     rv['version'] = '-'.join(desc.strip().split('-')[:2]).lstrip('v')
     rv['commit'], rv['date'] = glog.strip().split(None, 1)
-    mx = re.search(r'(?m)^(\d+)\.(\d+)(?:-(\d+))?', rv['version'])
+    mx = re.search(r'(?m)^(\d+)\.(\d+)([ab]\d*)?(?:-(\d+))?', rv['version'])
     rv['major'] = int(mx.group(1))
     rv['minor'] = int(mx.group(2))
-    rv['number'] = mx.group(3) and int(mx.group(3)) or 0
+    rv['prerelease'] = mx.group(3)
+    rv['number'] = mx.group(4) and int(mx.group(4)) or 0
     _cached_gitinfo = rv
     return gitinfo()
 

src/diffpy/SConscript.version

@@ -18,6 +18,8 @@ def build_VersionCode(target, source, env):
     tplcode = source[0].get_contents()
     numversion = (1000000 * ginfo['major'] +
             1000 * ginfo['minor'] + ginfo['number'])
+    if ginfo['prerelease']:
+        numversion = "(-500 + %i)" % numversion
     flds = {
         'DIFFPY_VERSION' : numversion,
         'DIFFPY_VERSION_MAJOR' : ginfo['major'],