issue/136 Fix following CR

src/datastruct/stacker/heap.rs

@@ -80,8 +80,14 @@ impl Heap {
     pub fn set<Item>(&self, addr: u32, val: &Item) {
         self.inner().set(addr, val);
     }
-    
-    /// Returns a mutable reference for an object at a given Item.
+
+    /// Returns a reference to an `Item` at a given `addr`.
+    #[cfg(test)]
+    pub fn get_ref<Item>(&self, addr: u32) -> &Item {
+        self.inner().get_mut_ref(addr)
+    }
+
+    /// Returns a mutable reference to an `Item` at a given `addr`.
     pub fn get_mut_ref<Item>(&self, addr: u32) -> &mut Item {
         self.inner().get_mut_ref(addr)
     }

src/indexer/merger.rs

@@ -202,7 +202,7 @@ impl IndexMerger {
             merged_doc_id_map.push(segment_local_map);
         }
 
-        let mut field = Field(u32::max_value());
+        let mut last_field: Option<Field> = None;
         
         while merged_terms.advance() {
             // Create the total list of doc ids
@@ -239,10 +239,11 @@ impl IndexMerger {
                         if let Some(remapped_doc_id) = old_to_new_doc_id[segment_postings.doc() as usize] {
                             if !term_written {
                                 let current_field = term.field();
-                                if current_field != field {
+                                if last_field != Some(current_field) {
                                     postings_serializer.new_field(current_field);
-                                    field = current_field;
+                                    last_field = Some(current_field);
                                 }
+                                
                                 // we make sure to only write the term iff
                                 // there is at least one document.
                                 postings_serializer.new_term(term.as_slice())?;

src/indexer/segment_writer.rs

@@ -98,8 +98,7 @@ impl<'a> SegmentWriter<'a> {
 	/// Return true if the term dictionary hashmap is reaching capacity.
 	/// It is one of the condition that triggers a `SegmentWriter` to
 	/// be finalized.
-	#[doc(hidden)]
-	pub fn is_termdic_saturated(&self,) -> bool {
+	pub(crate) fn is_termdic_saturated(&self,) -> bool {
 		self.multifield_postings.is_termdic_saturated()
 	}
 	
@@ -195,12 +194,10 @@ fn write<'a>(
 	  	mut serializer: SegmentSerializer) -> Result<()> {
 		
 		try!(multifield_postings.serialize(serializer.get_postings_serializer()));
-		// for per_field_postings_writer in per_field_postings_writers {
-		// 	try!(per_field_postings_writer.serialize(serializer.get_postings_serializer(), heap));
-		// }
 		try!(fast_field_writers.serialize(serializer.get_fast_field_serializer()));
 		try!(fieldnorms_writer.serialize(serializer.get_fieldnorms_serializer()));
 		try!(serializer.close());
+
 		Ok(())
 }
 

src/schema/term.rs

@@ -16,7 +16,6 @@ const INT_TERM_LEN: usize = 4 + 8;
 pub struct Term(Vec<u8>);
 
 /// Extract `field` from Term.
-#[doc(hidden)]
 pub(crate) fn extract_field_from_term_bytes(term_bytes: &[u8]) -> Field {
     Field(BigEndian::read_u32(&term_bytes[..4]))
 }