git hook handler shouldn't ever use cache instances

 - moved cache invalidation into finally block so we invalidate at latest possible stage
 - added scm_instance_no_cache property to get non cached scm instances always

rhodecode/lib/hooks.py

@@ -382,7 +382,12 b' def handle_git_receive(repo_path, revs, '
 
     for k, v in extras.items():
         baseui.setconfig('rhodecode_extras', k, v)
-    repo = repo.scm_instance
+    if hook_type == 'pre':
+        repo = repo.scm_instance
+    else:
+        #post push shouldn't use the cached instance never
+        repo = repo.scm_instance_no_cache
+
     repo.ui = baseui
 
     if hook_type == 'pre':

rhodecode/lib/middleware/simplegit.py

@@ -229,9 +229,6 b' class SimpleGit(BaseVCSController):'
 
         try:
             self._handle_githooks(repo_name, action, baseui, environ)
-            # invalidate cache on push
-            if action == 'push':
-                self._invalidate_cache(repo_name)
             log.info('%s action on GIT repo "%s" by "%s" from %s' %
                      (action, repo_name, username, ip_addr))
             app = self.__make_app(repo_name, repo_path, extras)
@@ -242,6 +239,10 b' class SimpleGit(BaseVCSController):'
         except Exception:
             log.error(traceback.format_exc())
             return HTTPInternalServerError()(environ, start_response)
+        finally:
+            # invalidate cache on push
+            if action == 'push':
+                self._invalidate_cache(repo_name)
 
     def __make_app(self, repo_name, repo_path, extras):
         """

rhodecode/lib/middleware/simplehg.py

@@ -191,9 +191,6 b' class SimpleHg(BaseVCSController):'
         self.__inject_extras(repo_path, baseui, extras)
 
         try:
-            # invalidate cache on push
-            if action == 'push':
-                self._invalidate_cache(repo_name)
             log.info('%s action on HG repo "%s" by "%s" from %s' %
                      (action, repo_name, username, ip_addr))
             app = self.__make_app(repo_path, baseui, extras)
@@ -207,6 +204,10 b' class SimpleHg(BaseVCSController):'
         except Exception:
             log.error(traceback.format_exc())
             return HTTPInternalServerError()(environ, start_response)
+        finally:
+            # invalidate cache on push
+            if action == 'push':
+                self._invalidate_cache(repo_name)
 
     def __make_app(self, repo_name, baseui, extras):
         """

rhodecode/model/db.py

@@ -1096,6 +1096,10 b' class Repository(Base, BaseModel):'
         CacheInvalidation.set_invalidate(repo_name=self.repo_name)
 
     @LazyProperty
+    def scm_instance_no_cache(self):
+        return self.__get_instance()
+
+    @LazyProperty
     def scm_instance(self):
         import rhodecode
         full_cache = str2bool(rhodecode.CONFIG.get('vcs_full_cache'))