From b7d46723fc704eb37555ac5dce96eab1724bdc2e Mon Sep 17 00:00:00 2001
From: Adam Kocoloski <adam@cloudant.com>
Date: Thu, 17 Jun 2010 12:34:11 -0400
Subject: updates to use 0.11-style missing_revs

---
 src/fabric_doc_missing_revs.erl |  2 +-
 src/fabric_rpc.erl              | 25 ++++++++++++++++++++++---
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/fabric_doc_missing_revs.erl b/src/fabric_doc_missing_revs.erl
index fe6deac6..8f1f5b4c 100644
--- a/src/fabric_doc_missing_revs.erl
+++ b/src/fabric_doc_missing_revs.erl
@@ -55,7 +55,7 @@ group_idrevs_by_shard(DbName, IdsRevs) ->
     end, dict:new(), IdsRevs)).
 
 update_dict(D0, KVs) ->
-    lists:foldl(fun({K,V}, D1) -> dict:store(K, V, D1) end, D0, KVs).
+    lists:foldl(fun({K,V,_}, D1) -> dict:store(K, V, D1) end, D0, KVs).
 
 skip_message({1, Dict}) ->
     {stop, dict:fold(fun force_reply/3, [], Dict)};
diff --git a/src/fabric_rpc.erl b/src/fabric_rpc.erl
index e9d9eb20..4b6e4e62 100644
--- a/src/fabric_rpc.erl
+++ b/src/fabric_rpc.erl
@@ -162,10 +162,11 @@ get_missing_revs(DbName, IdRevsList) ->
         Ids = [Id1 || {Id1, _Revs} <- IdRevsList],
         {ok, lists:zipwith(fun({Id, Revs}, FullDocInfoResult) ->
             case FullDocInfoResult of
-            {ok, #full_doc_info{rev_tree=RevisionTree}} ->
-                {Id, couch_key_tree:find_missing(RevisionTree, Revs)};
+            {ok, #full_doc_info{rev_tree=RevisionTree} = FullInfo} ->
+                MissingRevs = couch_key_tree:find_missing(RevisionTree, Revs),
+                {Id, MissingRevs, possible_ancestors(FullInfo, MissingRevs)};
             not_found ->
-                {Id, Revs}
+                {Id, Revs, []}
             end
         end, IdRevsList, couch_btree:lookup(Db#db.id_tree, Ids))};
     Error ->
@@ -304,3 +305,21 @@ doc_member(Shard, Id, Rev) ->
     Error ->
         Error
     end.
+
+possible_ancestors(_FullInfo, []) ->
+    [];
+possible_ancestors(FullInfo, MissingRevs) ->
+    #doc_info{revs=RevsInfo} = couch_doc:to_doc_info(FullInfo),
+    LeafRevs = [Rev || #rev_info{rev=Rev} <- RevsInfo],
+    % Find the revs that are possible parents of this rev
+    lists:foldl(fun({LeafPos, LeafRevId}, Acc) ->
+        % this leaf is a "possible ancenstor" of the missing 
+        % revs if this LeafPos lessthan any of the missing revs
+        case lists:any(fun({MissingPos, _}) -> 
+                LeafPos < MissingPos end, MissingRevs) of
+        true ->
+            [{LeafPos, LeafRevId} | Acc];
+        false ->
+            Acc
+        end
+    end, [], LeafRevs).
-- 
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