add a function to query for the svn revision of the mapnik python bindings

SConstruct

@@ -824,11 +824,21 @@ if not preconfigured:
         else:
             env['ABI_VERSION'] = abi
 
+
         # Common C++ flags.
         if env['THREADING'] == 'multi' :
             common_cxx_flags = '-D%s -DBOOST_SPIRIT_THREADSAFE -DMAPNIK_THREADSAFE ' % env['PLATFORM'].upper()
         else :
             common_cxx_flags = '-D%s ' % env['PLATFORM'].upper()
+
+        
+        svn_version = call('svnversion')
+        if svn_version == 'exported':
+            pattern = r'(\d+)(.*)'
+            try:
+                rev = re.match(pattern,svn_version).groups()[0]
+                common_cxx_flags += '-DSVN_REVISION=%s ' % rev
+            except: pass
             
         # Mac OSX (Darwin) special settings
         if env['PLATFORM'] == 'Darwin':

bindings/python/mapnik_python.cpp

@@ -222,6 +222,15 @@ unsigned mapnik_version()
     return MAPNIK_VERSION;
 }
 
+unsigned mapnik_svn_revision()
+{
+#if defined(SVN_REVISION)
+  return SVN_REVISION;
+#else
+  return 0;
+#endif
+}
+
 bool has_cairo()
 {
 #if defined(HAVE_CAIRO) && defined(HAVE_PYCAIRO)
@@ -434,6 +443,7 @@ BOOST_PYTHON_MODULE(_mapnik)
 */
 
     def("mapnik_version", &mapnik_version,"Get the Mapnik version number");
+    def("mapnik_svn_revision", &mapnik_svn_revision,"Get the Mapnik svn revision");
     def("has_cairo", &has_cairo, "Get cairo library status");
     
     using mapnik::symbolizer;