Fix for COUCHDB-300. Old seq were being removed when a conflict. An old bug, but recent changes made it much more likely to happen.

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@756925 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 19 insertions, 13 deletions

diff --git a/etc/couchdb/local_dev.ini b/etc/couchdb/local_dev.ini
index 54c75bde..876295b1 100644
--- a/etc/couchdb/local_dev.ini
+++ b/etc/couchdb/local_dev.ini
@@ -12,7 +12,7 @@
 ;bind_address = 127.0.0.1
 
 [log]
-; level = debug
+level = error
 
 [update_notification]
 ;unique notifier name=/full/path/to/exe -with "cmd line arg"
diff --git a/share/www/script/test/conflicts.js b/share/www/script/test/conflicts.js
index 02e50035..dfd7e8b6 100644
--- a/share/www/script/test/conflicts.js
+++ b/share/www/script/test/conflicts.js
@@ -41,6 +41,10 @@ couchTests.conflicts = function(debug) {
   } catch (e) {
     T(e.error == "conflict");
   }
+   
+  var bySeq = db.allDocsBySeq();
+
+  T( bySeq.rows.length == 1)
 
   // Now clear out the _rev member and save. This indicates this document is
   // new, not based on an existing revision.
diff --git a/src/couchdb/couch_db_updater.erl b/src/couchdb/couch_db_updater.erl
index 7752a577..969a79d4 100644
--- a/src/couchdb/couch_db_updater.erl
+++ b/src/couchdb/couch_db_updater.erl
@@ -357,11 +357,12 @@ flush_trees(#db{fd=Fd}=Db, [InfoUnflushed | RestUnflushed], AccFlushed) ->
         end, Unflushed),
     flush_trees(Db, RestUnflushed, [InfoUnflushed#full_doc_info{rev_tree=Flushed} | AccFlushed]).
 
-merge_rev_trees(_MergeConflicts, [], [], AccNewInfos, AccConflicts, AccSeq) ->
-    {ok, lists:reverse(AccNewInfos), AccConflicts, AccSeq};
+merge_rev_trees(_MergeConflicts, [], [], AccNewInfos, AccRemoveSeqs, AccConflicts, AccSeq) ->
+    {ok, lists:reverse(AccNewInfos), AccRemoveSeqs, AccConflicts, AccSeq};
 merge_rev_trees(MergeConflicts, [NewDocs|RestDocsList],
-        [OldDocInfo|RestOldInfo], AccNewInfos, AccConflicts, AccSeq) ->
-    #full_doc_info{id=Id,rev_tree=OldTree,deleted=OldDeleted}=OldDocInfo,
+        [OldDocInfo|RestOldInfo], AccNewInfos, AccRemoveSeqs, AccConflicts, AccSeq) ->
+    #full_doc_info{id=Id,rev_tree=OldTree,deleted=OldDeleted,update_seq=OldSeq}
+            = OldDocInfo,
     {NewRevTree, NewConflicts} = lists:foldl(
         fun(#doc{revs={Pos,[Rev|_]}}=NewDoc, {AccTree, AccConflicts2}) ->
             case couch_key_tree:merge(AccTree, [couch_db:doc_to_tree(NewDoc)]) of
@@ -376,12 +377,16 @@ merge_rev_trees(MergeConflicts, [NewDocs|RestDocsList],
     if NewRevTree == OldTree ->
         % nothing changed
         merge_rev_trees(MergeConflicts, RestDocsList, RestOldInfo, AccNewInfos,
-                NewConflicts, AccSeq);
+                AccRemoveSeqs, NewConflicts, AccSeq);
     true ->
         % we have updated the document, give it a new seq #
         NewInfo = #full_doc_info{id=Id,update_seq=AccSeq+1,rev_tree=NewRevTree},
-        merge_rev_trees(MergeConflicts, RestDocsList,RestOldInfo, 
-                [NewInfo|AccNewInfos], NewConflicts, AccSeq+1)
+        RemoveSeqs = case OldSeq of
+            0 -> AccRemoveSeqs;
+            _ -> [OldSeq | AccRemoveSeqs]
+        end,
+        merge_rev_trees(MergeConflicts, RestDocsList, RestOldInfo, 
+                [NewInfo|AccNewInfos], RemoveSeqs, NewConflicts, AccSeq+1)
     end.
 
 new_index_entries([], AccById, AccBySeq) ->
@@ -428,15 +433,12 @@ update_docs_int(Db, DocsList, Options) ->
         Ids, OldDocLookups),
     
     % Merge the new docs into the revision trees.
-    {ok, NewDocInfos0, Conflicts, NewSeq} = merge_rev_trees(
+    {ok, NewDocInfos0, RemoveSeqs, Conflicts, NewSeq} = merge_rev_trees(
             lists:member(merge_conflicts, Options),
-            DocsList2, OldDocInfos, [], [], LastSeq),
+            DocsList2, OldDocInfos, [], [], [], LastSeq),
     
     NewDocInfos = stem_full_doc_infos(Db, NewDocInfos0),
     
-    RemoveSeqs =
-        [OldSeq || {ok, #full_doc_info{update_seq=OldSeq}} <- OldDocLookups],
-    
     % All documents are now ready to write.
     
     {ok, LocalConflicts, Db2}  = update_local_docs(Db, NonRepDocs),