Stem revision trees after merging a path, COUCHDB-968

git-svn-id: https://svn.apache.org/repos/asf/couchdb/branches/1.1.x@1053513 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 29 insertions, 25 deletions

diff --git a/src/couchdb/couch_db.erl b/src/couchdb/couch_db.erl
index 4e945ad4..7522a189 100644
--- a/src/couchdb/couch_db.erl
+++ b/src/couchdb/couch_db.erl
@@ -555,7 +555,8 @@ prep_and_validate_replicated_updates(Db, [Bucket|RestBuckets], [OldInfo|RestOldI
     {ok, #full_doc_info{rev_tree=OldTree}} ->
         NewRevTree = lists:foldl(
             fun(NewDoc, AccTree) ->
-                {NewTree, _} = couch_key_tree:merge(AccTree, couch_db:doc_to_tree(NewDoc)),
+                {NewTree, _} = couch_key_tree:merge(AccTree,
+                    couch_db:doc_to_tree(NewDoc), Db#db.revs_limit),
                 NewTree
             end,
             OldTree, Bucket),
diff --git a/src/couchdb/couch_db_updater.erl b/src/couchdb/couch_db_updater.erl
index 2cce4b69..eb1a3edc 100644
--- a/src/couchdb/couch_db_updater.erl
+++ b/src/couchdb/couch_db_updater.erl
@@ -495,10 +495,11 @@ merge_rev_trees(Limit, MergeConflicts, [NewDocs|RestDocsList],
         [OldDocInfo|RestOldInfo], AccNewInfos, AccRemoveSeqs, AccSeq) ->
     #full_doc_info{id=Id,rev_tree=OldTree,deleted=OldDeleted,update_seq=OldSeq}
             = OldDocInfo,
-    NewRevTree0 = lists:foldl(
+    NewRevTree = lists:foldl(
         fun({Client, #doc{revs={Pos,[_Rev|PrevRevs]}}=NewDoc}, AccTree) ->
             if not MergeConflicts ->
-                case couch_key_tree:merge(AccTree, couch_db:doc_to_tree(NewDoc)) of
+                case couch_key_tree:merge(AccTree, couch_db:doc_to_tree(NewDoc),
+                    Limit) of
                 {_NewTree, conflicts} when (not OldDeleted) ->
                     send_result(Client, Id, {Pos-1,PrevRevs}, conflict),
                     AccTree;
@@ -529,7 +530,7 @@ merge_rev_trees(Limit, MergeConflicts, [NewDocs|RestDocsList],
                                 NewDoc#doc{revs={OldPos, [OldRev]}}),
                         NewDoc2 = NewDoc#doc{revs={OldPos + 1, [NewRevId, OldRev]}},
                         {NewTree2, _} = couch_key_tree:merge(AccTree,
-                                couch_db:doc_to_tree(NewDoc2)),
+                                couch_db:doc_to_tree(NewDoc2), Limit),
                         % we changed the rev id, this tells the caller we did
                         send_result(Client, Id, {Pos-1,PrevRevs},
                                 {ok, {OldPos + 1, NewRevId}}),
@@ -543,12 +544,11 @@ merge_rev_trees(Limit, MergeConflicts, [NewDocs|RestDocsList],
                 end;
             true ->
                 {NewTree, _} = couch_key_tree:merge(AccTree,
-                            couch_db:doc_to_tree(NewDoc)),
+                            couch_db:doc_to_tree(NewDoc), Limit),
                 NewTree
             end
         end,
         OldTree, NewDocs),
-    NewRevTree = couch_key_tree:stem(NewRevTree0, Limit),
     if NewRevTree == OldTree ->
         % nothing changed
         merge_rev_trees(Limit, MergeConflicts, RestDocsList, RestOldInfo,
diff --git a/src/couchdb/couch_key_tree.erl b/src/couchdb/couch_key_tree.erl
index 09712adf..bc723cc2 100644
--- a/src/couchdb/couch_key_tree.erl
+++ b/src/couchdb/couch_key_tree.erl
@@ -12,7 +12,7 @@
 
 -module(couch_key_tree).
 
--export([merge/2, find_missing/2, get_key_leafs/2, get_full_key_paths/2, get/2]).
+-export([merge/3, find_missing/2, get_key_leafs/2, get_full_key_paths/2, get/2]).
 -export([map/2, get_all_leafs/1, count_leafs/1, remove_leafs/2,
     get_all_leafs_full/1,stem/2,map_leafs/2]).
 
@@ -23,6 +23,12 @@
 
 % partial trees arranged by how much they are cut off.
 
+-spec merge([path()], path(), pos_integer()) -> {[path()],
+    conflicts | no_conflicts}.
+merge(Paths, Path, Depth) ->
+    {Merged, Conflicts} = merge(Paths, Path),
+    {stem(Merged, Depth), Conflicts}.
+
 -spec merge([path()], path()) -> {[path()], conflicts | no_conflicts}.
 merge(Paths, Path) ->
     {ok, Merged, HasConflicts} = merge_one(Paths, Path, [], false),
diff --git a/test/etap/060-kt-merging.t b/test/etap/060-kt-merging.t
index 971e49bf..0e481a52 100755
--- a/test/etap/060-kt-merging.t
+++ b/test/etap/060-kt-merging.t
@@ -15,7 +15,7 @@
 
 main(_) ->
     test_util:init_code_path(),
-    etap:plan(14),
+    etap:plan(12),
     case (catch test()) of
         ok ->
             etap:end_tests();
@@ -42,77 +42,74 @@ test() ->
 
     etap:is(
         {[One], no_conflicts},
-        couch_key_tree:merge([], One),
+        couch_key_tree:merge([], One, 10),
         "The empty tree is the identity for merge."
     ),
 
     etap:is(
         {TwoSibs, no_conflicts},
-        couch_key_tree:merge(TwoSibs, One),
+        couch_key_tree:merge(TwoSibs, One, 10),
         "Merging a prefix of a tree with the tree yields the tree."
     ),
 
     etap:is(
         {[One], no_conflicts},
-        couch_key_tree:merge([One], One),
+        couch_key_tree:merge([One], One, 10),
         "Merging is reflexive."
     ),
 
     etap:is(
         {[TwoChild], no_conflicts},
-        couch_key_tree:merge([TwoChild], TwoChild),
+        couch_key_tree:merge([TwoChild], TwoChild, 10),
         "Merging two children is still reflexive."
     ),
 
     etap:is(
         {[TwoChildSibs], no_conflicts},
-        couch_key_tree:merge([TwoChildSibs], TwoChildSibs),
+        couch_key_tree:merge([TwoChildSibs], TwoChildSibs, 10),
         "Merging a tree to itself is itself."),
 
     etap:is(
         {[TwoChildSibs], no_conflicts},
-        couch_key_tree:merge([TwoChildSibs], Stemmed1b),
+        couch_key_tree:merge([TwoChildSibs], Stemmed1b, 10),
         "Merging a tree with a stem."
     ),
 
     etap:is(
         {[TwoChildSibs2], no_conflicts},
-        couch_key_tree:merge([TwoChildSibs2], Stemmed1bb),
+        couch_key_tree:merge([TwoChildSibs2], Stemmed1bb, 10),
         "Merging a stem at a deeper level."
     ),
 
     etap:is(
         {[TwoChild], no_conflicts},
-        couch_key_tree:merge([TwoChild], Stemmed1aa),
+        couch_key_tree:merge([TwoChild], Stemmed1aa, 10),
         "Merging a single tree with a deeper stem."
     ),
 
     etap:is(
         {[TwoChild], no_conflicts},
-        couch_key_tree:merge([TwoChild], Stemmed1a),
+        couch_key_tree:merge([TwoChild], Stemmed1a, 10),
         "Merging a larger stem."
     ),
 
     etap:is(
         {[Stemmed1a], no_conflicts},
-        couch_key_tree:merge([Stemmed1a], Stemmed1aa),
+        couch_key_tree:merge([Stemmed1a], Stemmed1aa, 10),
         "More merging."
     ),
 
     Expect1 = [OneChild, Stemmed1aa],
     etap:is(
         {Expect1, conflicts},
-        couch_key_tree:merge([OneChild], Stemmed1aa),
+        couch_key_tree:merge([OneChild], Stemmed1aa, 10),
         "Merging should create conflicts."
     ),
 
-    {MultiPaths, NoConflicts} = couch_key_tree:merge(Expect1, TwoChild),
-    etap:is(NoConflicts, no_conflicts, "Merge should have no conflicts."),
-    etap:is(length(MultiPaths), 2, "Should have two paths before stemming."),
     etap:is(
-        couch_key_tree:stem(MultiPaths, 10),
-        [TwoChild],
-        "Stemming should collapse the paths."
+        {[TwoChild], no_conflicts},
+        couch_key_tree:merge(Expect1, TwoChild, 10),
+        "Merge should have no conflicts."
     ),
 
     ok.