[t:2403], set last_dup_key in update_row

git-svn-id: file:///svn/mysql/tokudb-engine/tokudb-engine@18045 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.cc

@@ -3439,7 +3439,10 @@ int ha_tokudb::update_row(const uchar * old_row, uchar * new_row) {
             );
         lockretry_wait;
     }
-    if (!error) {
+    if (error == DB_KEYEXIST) {
+        last_dup_key = primary_key;
+    }    
+    else if (!error) {
         trx->stmt_progress.updated++;
         track_progress(thd);
     }