Fixed bug with indexing into repeated fields.

Fixes #3

Author: mpartel

expected/postgres_protobuf.out

@@ -361,6 +361,14 @@ SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[1].repeated_inner
 result
 bbb
 (1 row)
+SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].inner_str', '\x2a0e0a046c766c311a060a046c766c32'::BYTEA) AS result;
+result
+lvl1
+(1 row)
+SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].repeated_inner[0].inner_str', '\x2a0e0a046c766c311a060a046c766c32'::BYTEA) AS result;
+result
+lvl2
+(1 row)
 --
 -- Indexing into maps
 --

generate_test_cases.rb

@@ -280,6 +280,11 @@ def pg_quote(s)
       test_sql("SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[1].repeated_inner[0].inner_str', #{pg_proto}) AS result;", ['aaa'])
       test_sql("SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[1].repeated_inner[1].inner_str', #{pg_proto}) AS result;", ['bbb'])
     end
+
+    with_proto('repeated_inner: { inner_str: "lvl1", repeated_inner: { inner_str: "lvl2" } }') do
+      test_sql("SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].inner_str', #{pg_proto}) AS result;", ['lvl1'])
+      test_sql("SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].repeated_inner[0].inner_str', #{pg_proto}) AS result;", ['lvl2'])
+    end
   end
 
   section "Indexing into maps" do

querying.cpp

@@ -613,6 +613,7 @@ class FieldSelector : public ProtobufVisitor {
         is_packed_(is_packed),
         wanted_index_(-1),
         state_(State::Scanning),
+        current_field_(0),
         current_index_(0) {
     PGPROTO_DEBUG("Created field selector %d %lx", wanted_field,
                   intptr_t(this));
@@ -623,19 +624,20 @@ class FieldSelector : public ProtobufVisitor {
   void Pushed(ProtobufTraverser* traverser) override { traverser_ = traverser; }
 
   ProtobufVisitor* BeginField(int number, int wire_type) override {
+    current_field_ = number;
     if (wire_type == 2) {
       if (is_packed_) {
         state_ = State::EmittingPacked;
       } else {
-        if (WantThisField(number)) {
+        if (ShouldEmitCurrentIndex()) {
           if (ty_ == pb::FieldDescriptor::Type::TYPE_MESSAGE) {
             return next_;
           } else {
             state_ = State::EmittingOtherComposite;
           }
         }
       }
-    } else if (WantThisField(number)) {
+    } else if (ShouldEmitCurrentIndex()) {
       return next_;
     }
     return this;
@@ -645,7 +647,7 @@ class FieldSelector : public ProtobufVisitor {
   ReadLengthDelimitedField(const FieldInfo& field) override {
     if (state_ == State::EmittingPacked) {
       return std::make_pair(PackedCompositeFieldTreatmentForType(ty_), this);
-    } else if (WantThisField(field.number)) {
+    } else if (ShouldEmitCurrentIndex()) {
       if (state_ == State::EmittingOtherComposite) {
         return std::make_pair(CompositeFieldTreatmentForType(ty_), next_);
       } else {
@@ -656,10 +658,15 @@ class FieldSelector : public ProtobufVisitor {
     }
   }
 
-  void EndField() override { ++current_index_; }
+  void EndField() override {
+    if (current_field_ == wanted_field_) {
+      ++current_index_;
+    }
+  }
 
   void Popped() override {
     state_ = State::Scanning;
+    current_field_ = 0;
     current_index_ = 0;
   }
 
@@ -676,10 +683,11 @@ class FieldSelector : public ProtobufVisitor {
     EmittingOtherComposite,
   };
   State state_;
+  int current_field_;
   int current_index_;
 
-  bool WantThisField(int number) const {
-    return number == wanted_field_ &&
+  bool ShouldEmitCurrentIndex() const {
+    return current_field_ == wanted_field_ &&
            (wanted_index_ == -1 || current_index_ == wanted_index_);
   }
 };

sql/postgres_protobuf.sql

@@ -185,6 +185,8 @@ SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].repeated_inner
 SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].repeated_inner[1].inner_str', '\x2a0e1a050a036162631a050a036465662a0e1a050a036161611a050a03626262'::BYTEA) AS result;
 SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[1].repeated_inner[0].inner_str', '\x2a0e1a050a036162631a050a036465662a0e1a050a036161611a050a03626262'::BYTEA) AS result;
 SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[1].repeated_inner[1].inner_str', '\x2a0e1a050a036162631a050a036465662a0e1a050a036161611a050a03626262'::BYTEA) AS result;
+SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].inner_str', '\x2a0e0a046c766c311a060a046c766c32'::BYTEA) AS result;
+SELECT protobuf_query('pgpb.test.ExampleMessage:repeated_inner[0].repeated_inner[0].inner_str', '\x2a0e0a046c766c311a060a046c766c32'::BYTEA) AS result;
 --
 -- Indexing into maps
 --