Add script to load openttd revisions for joining old servers

gen_newgrf_revisions.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+
+from urllib.request import urlopen
+
+verstr = urlopen("http://finger.openttd.org/tags.txt").read()
+verstr = verstr.decode('utf-8')
+verdata = verstr.strip().split()
+
+releases = []
+f = open("src/newgrf_revisions.cpp", "w")
+f.write('#include "stdafx.h"\n\n')
+f.write('#include <map>\n')
+
+f.write('const std::map<std::string, uint32> OPENTTD_NEWGRF_VERSIONS = {\n')
+for rev, ver in zip(map(int, verdata[0::3]), verdata[2::3]):
+    if ver.startswith('1.1'):
+        break
+    v = ver.split('.')
+    vr = None
+    if '-' in v[2]:
+        v[2], vr = v[2].split('-')
+    v = list(map(int, v))
+    release_flag = int(not bool(vr))
+    newgrf_rev = (v[0] << 28 | v[1] << 24 | v[2] << 20 |
+                  release_flag << 19 | (rev & ((1 << 19) - 1)))
+    f.write('    {{"{}", {}}},\n'.format(ver, newgrf_rev))
+
+    if release_flag and v[2] == 0:
+        newgrf_rev = v[0] << 28 | (v[1] + 1) << 24
+        releases.append((rev, newgrf_rev))
+
+f.write('};\n\n')
+
+f.write('const std::map<uint32, uint32> OPENTTD_RELEASE_REVISIONS = {\n')
+for rev, newgrf_rev in releases:
+    f.write('    {{{}, {}}},\n'.format(rev, newgrf_rev))
+f.write('};\n')