Fix server version parsing when it contains trailing data

Some distros (e.g Debian) like may inject their branding
into the numeric version string, so make sure to only look
at stuff before the first space.

Fixes: #250.

Author: elprans

asyncpg/serverversion.py

@@ -13,8 +13,12 @@ def split_server_version_string(version_string):
     if version_string.startswith('PostgreSQL '):
         version_string = version_string[len('PostgreSQL '):]
     if version_string.startswith('Postgres-XL'):
-        version_string = version_string[len('Postgre-XL '):]
+        version_string = version_string[len('Postgres-XL '):]
 
+    # Some distros (e.g Debian) like may inject their branding
+    # into the numeric version string, so make sure to only look
+    # at stuff before the first space.
+    version_string = version_string.split(' ')[0]
     parts = version_string.strip().split('.')
     if not parts[-1].isdigit():
         # release level specified

tests/test_connect.py

@@ -49,14 +49,15 @@ async def test_server_version_01(self):
     def test_server_version_02(self):
         versions = [
             ("9.2", (9, 2, 0, 'final', 0),),
-            ("9.2.1", (9, 2, 1, 'final', 0),),
+            ("Postgres-XL 9.2.1", (9, 2, 1, 'final', 0),),
             ("9.4beta1", (9, 4, 0, 'beta', 1),),
             ("10devel", (10, 0, 0, 'devel', 0),),
             ("10beta2", (10, 0, 0, 'beta', 2),),
             # For PostgreSQL versions >=10 we always
             # set version.minor to 0.
             ("10.1", (10, 0, 1, 'final', 0),),
             ("11.1.2", (11, 0, 1, 'final', 0),),
+            ("PostgreSQL 10.1 (Debian 10.1-3)", (10, 0, 1, 'final', 0),),
         ]
         for version, expected in versions:
             result = split_server_version_string(version)