Check if db exists in /db/_ensure_full_commit call (#1588)

We removed a security call in `do_db_req` to avoid
a duplicate authorization check and as a result
there are now no db validation in noop call
`/db/_ensure_full_commit`. This makes it always
return a success code, even for missing databases.

This fix places the security check back, directly
in _ensure_full_commit call and adds eunit tests
for a good measure.

2 files changed, 28 insertions, 1 deletions

diff --git a/src/chttpd/src/chttpd_db.erl b/src/chttpd/src/chttpd_db.erl
index d3655c35d..49d7b5849 100644
--- a/src/chttpd/src/chttpd_db.erl
+++ b/src/chttpd/src/chttpd_db.erl
@@ -375,8 +375,13 @@ db_req(#httpd{method='POST', path_parts=[DbName], user_ctx=Ctx}=Req, Db) ->
 db_req(#httpd{path_parts=[_DbName]}=Req, _Db) ->
     send_method_not_allowed(Req, "DELETE,GET,HEAD,POST");
 
-db_req(#httpd{method='POST',path_parts=[_,<<"_ensure_full_commit">>]}=Req, _Db) ->
+db_req(#httpd{method='POST', path_parts=[DbName, <<"_ensure_full_commit">>],
+        user_ctx=Ctx}=Req, _Db) ->
     chttpd:validate_ctype(Req, "application/json"),
+    %% use fabric call to trigger a database_does_not_exist exception
+    %% for missing databases that'd return error 404 from chttpd
+    %% get_security used to prefer shards on the same node over other nodes
+    fabric:get_security(DbName, [{user_ctx, Ctx}]),
     send_json(Req, 201, {[
         {ok, true},
         {instance_start_time, <<"0">>}
diff --git a/src/chttpd/test/chttpd_db_test.erl b/src/chttpd/test/chttpd_db_test.erl
index 636603710..2708aa033 100644
--- a/src/chttpd/test/chttpd_db_test.erl
+++ b/src/chttpd/test/chttpd_db_test.erl
@@ -61,6 +61,8 @@ all_test_() ->
                 fun setup/0, fun teardown/1,
                 [
                     fun should_return_ok_true_on_bulk_update/1,
+                    fun should_return_ok_true_on_ensure_full_commit/1,
+                    fun should_return_404_for_ensure_full_commit_on_no_db/1,
                     fun should_accept_live_as_an_alias_for_continuous/1,
                     fun should_return_404_for_delete_att_on_notadoc/1,
                     fun should_return_409_for_del_att_without_rev/1,
@@ -100,6 +102,26 @@ should_return_ok_true_on_bulk_update(Url) ->
         end).
 
 
+should_return_ok_true_on_ensure_full_commit(Url0) ->
+    ?_test(begin
+        Url = Url0 ++ "/_ensure_full_commit",
+        {ok, RC, _, Body} = test_request:post(Url, [?CONTENT_JSON, ?AUTH], []),
+        {Json} = ?JSON_DECODE(Body),
+        ?assertEqual(201, RC),
+        ?assert(couch_util:get_value(<<"ok">>, Json))
+    end).
+
+
+should_return_404_for_ensure_full_commit_on_no_db(Url0) ->
+    ?_test(begin
+        Url = Url0 ++ "-missing-db" ++ "/_ensure_full_commit",
+        {ok, RC, _, Body} = test_request:post(Url, [?CONTENT_JSON, ?AUTH], []),
+        {Json} = ?JSON_DECODE(Body),
+        ?assertEqual(404, RC),
+        ?assertEqual(<<"not_found">>, couch_util:get_value(<<"error">>, Json))
+    end).
+
+
 should_accept_live_as_an_alias_for_continuous(Url) ->
     GetLastSeq = fun(Bin) ->
         Parts = binary:split(Bin, <<"\n">>, [global]),