From 4b001e1842f5043459d98f1429b0ffaf7f905cd4 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <tg@realm.io>
Date: Thu, 7 Jan 2016 14:27:53 -0800
Subject: [PATCH] Extract some logic to a helper function to avoid recursion in
 update_schema()

---
 src/shared_realm.cpp | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/shared_realm.cpp b/src/shared_realm.cpp
index 8f51a96e..4720582c 100644
--- a/src/shared_realm.cpp
+++ b/src/shared_realm.cpp
@@ -201,12 +201,20 @@ void Realm::update_schema(std::unique_ptr<Schema> schema, uint64_t version)
 {
     schema->validate();
 
-    // If the schema version matches, just verify that the schema itself also matches
-    bool needs_update = !m_config.read_only && (m_config.schema_version != version || ObjectStore::needs_update(*m_config.schema, *schema));
-    if (!needs_update) {
+    auto needs_update = [&] {
+        // If the schema version matches, just verify that the schema itself also matches
+        bool needs_write = !m_config.read_only && (m_config.schema_version != version || ObjectStore::needs_update(*m_config.schema, *schema));
+        if (needs_write) {
+            return true;
+        }
+
         ObjectStore::verify_schema(*m_config.schema, *schema, m_config.read_only);
         m_config.schema = std::move(schema);
         m_config.schema_version = version;
+        return false;
+    };
+
+    if (!needs_update()) {
         return;
     }
 
@@ -225,11 +233,13 @@ void Realm::update_schema(std::unique_ptr<Schema> schema, uint64_t version)
     // recheck everything
     auto current_schema_version = ObjectStore::get_schema_version(read_group());
     if (current_schema_version != m_config.schema_version) {
-        cancel_transaction();
-
         m_config.schema_version = current_schema_version;
         *m_config.schema = ObjectStore::schema_from_group(read_group());
-        return update_schema(std::move(schema), version);
+
+        if (!needs_update()) {
+            cancel_transaction();
+            return;
+        }
     }
 
     Config old_config(m_config);