Fix badmatch in couch_views_indexer

Previously, when an erlfdb error occured and a recursive call to `update/3` was
made, the result of that call was always matched against `{Mrst, State}`.
However, in the case when the call had finalized and returned
`couch_eval:release_map_context/1` response, the result would be `ok` which
would blow with a badmatch error against `{Mrst, State}`.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/couch_views/src/couch_views_indexer.erl b/src/couch_views/src/couch_views_indexer.erl
index e3b2ad5bc..8019d9f6a 100644
--- a/src/couch_views/src/couch_views_indexer.erl
+++ b/src/couch_views/src/couch_views_indexer.erl
@@ -182,17 +182,19 @@ add_error(Error, Reason, Data) ->
 
 update(#{} = Db, Mrst0, State0) ->
     Limit = couch_views_batch:start(Mrst0),
-    {Mrst1, State1} = try
+    Result = try
         do_update(Db, Mrst0, State0#{limit => Limit})
     catch
         error:{erlfdb_error, Error} when ?IS_RECOVERABLE_ERROR(Error) ->
             couch_views_batch:failure(Mrst0),
             update(Db, Mrst0, State0)
     end,
-    case State1 of
-        finished ->
+    case Result of
+        ok ->
+            ok; % Already finished and released map context
+        {Mrst1, finished} ->
             couch_eval:release_map_context(Mrst1#mrst.qserver);
-        _ ->
+        {Mrst1, State1} ->
             #{
                 update_stats := UpdateStats
             } = State1,