revert some unpackword code to see if more stable, more getsnippet tweaks, a=chris

diff --git a/lib/index_shard.php b/lib/index_shard.php
index e47d9b8a1..ea52b0a70 100644
--- a/lib/index_shard.php
+++ b/lib/index_shard.php
@@ -1520,8 +1520,6 @@ class IndexShard extends PersistentStructure implements
         }
         $num_lists = count($this->words);
         $cnt = 0;
-        $base_offset = 0;
-        $mega = 1000000;
         foreach($this->words as $word_id => $postings_info) {
             /* we are ignoring the first four bytes which contains
                generation info
@@ -1537,14 +1535,7 @@ class IndexShard extends PersistentStructure implements
                     8));
                 if(!isset($tmp[2])) {continue; }
                 list(, $offset, $len) = $tmp;
-                $diff_offset = $offset - $base_offset;
-                $postings = substr($this->word_docs, $diff_offset, $len);
-                if($diff_offset > $mega) {
-                    $num_megas = floor($diff_offset / $mega);
-                    $this->word_docs = substr($this->word_docs,
-                        $num_megas * $mega);
-                    $base_offset += $num_megas * $mega;
-                }
+                $postings = substr($this->word_docs, $offset, $len);
                 $this->words[$word_id] = $postings;
             }
             $cnt++;
diff --git a/models/model.php b/models/model.php
index dbb41b5a5..ab54825b4 100755
--- a/models/model.php
+++ b/models/model.php
@@ -263,23 +263,23 @@ class Model implements CrawlConstants
                 }
                 continue;
             }
-
-                $word_locations = array();
+            $word_locations = array();
             foreach($words as $word) {
                 $qword = "/".preg_quote($word)."/ui";
                 preg_match_all($qword, $text_source, $positions,
                     PREG_OFFSET_CAPTURE);
+
                 if(isset($positions[0]) && is_array($positions[0])) {
                     $positions = $positions[0];
                     foreach($positions as $position) {
-                        $word_locations[$position[1]] = $word;
+                        $word_locations[] = $position[1];
                     }
                 }

             }
             $high = 0;
-            ksort($word_locations);
-            foreach($word_locations as $pos => $word) {
+            sort($word_locations);
+            foreach($word_locations as $pos) {
                 if($pos < $high) continue;
                 $pre_low = ($pos >= SNIPPET_LENGTH_LEFT) ?
                     $pos - SNIPPET_LENGTH_LEFT: 0;