Changed mongoVersion and configVersion to optional for backwards compatibility

3 files changed, 33 insertions, 25 deletions

diff --git a/src/mongo/s/type_mongos.cpp b/src/mongo/s/type_mongos.cpp
index 8f5febb240b..ae515a94d9d 100644
--- a/src/mongo/s/type_mongos.cpp
+++ b/src/mongo/s/type_mongos.cpp
@@ -61,14 +61,6 @@ namespace mongo {
             *errMsg = stream() << "missing " << waiting.name() << " field";
             return false;
         }
-        if (!_isMongoVersionSet) {
-            *errMsg = stream() << "missing " << mongoVersion.name() << " field";
-            return false;
-        }
-        if (!_isConfigVersionSet) {
-            *errMsg = stream() << "missing " << configVersion.name() << " field";
-            return false;
-        }
 
         return true;
     }
diff --git a/src/mongo/s/type_mongos.h b/src/mongo/s/type_mongos.h
index d69290883b4..7c3d412bd6f 100644
--- a/src/mongo/s/type_mongos.h
+++ b/src/mongo/s/type_mongos.h
@@ -168,6 +168,7 @@ namespace mongo {
             return _waiting;
         }
 
+        // Optional Fields
         void setMongoVersion(const StringData& mongoVersion) {
             _mongoVersion = mongoVersion.toString();
             _isMongoVersionSet = true;
@@ -175,14 +176,20 @@ namespace mongo {
 
         void unsetMongoVersion() { _isMongoVersionSet = false; }
 
-        bool isMongoVersionSet() const { return _isMongoVersionSet; }
-
-        // Calling get*() methods when the member is not set results in undefined behavior
-        const std::string& getMongoVersion() const {
-            dassert(_isMongoVersionSet);
-            return _mongoVersion;
+        bool isMongoVersionSet() const {
+            return _isMongoVersionSet || mongoVersion.hasDefault();
         }
 
+        // Calling get*() methods when the member is not set and has no default results in undefined
+        // behavior
+        std::string getMongoVersion() const {
+            if (_isMongoVersionSet) {
+                return _mongoVersion;
+            } else {
+                dassert(mongoVersion.hasDefault());
+                return mongoVersion.getDefault();
+            }
+        }
         void setConfigVersion(const int configVersion) {
             _configVersion = configVersion;
             _isConfigVersionSet = true;
@@ -190,15 +197,20 @@ namespace mongo {
 
         void unsetConfigVersion() { _isConfigVersionSet = false; }
 
-        bool isConfigVersionSet() const { return _isConfigVersionSet; }
-
-        // Calling get*() methods when the member is not set results in undefined behavior
-        const int getConfigVersion() const {
-            dassert(_isConfigVersionSet);
-            return _configVersion;
+        bool isConfigVersionSet() const {
+            return _isConfigVersionSet || configVersion.hasDefault();
         }
 
-        // Optional Fields
+        // Calling get*() methods when the member is not set and has no default results in undefined
+        // behavior
+        int getConfigVersion() const {
+            if (_isConfigVersionSet) {
+                return _configVersion;
+            } else {
+                dassert(configVersion.hasDefault());
+                return configVersion.getDefault();
+            }
+        }
 
     private:
         // Convention: (M)andatory, (O)ptional, (S)pecial rule.
@@ -210,9 +222,9 @@ namespace mongo {
         bool _isUpSet;
         bool _waiting;     // (M)  for testing purposes
         bool _isWaitingSet;
-        std::string _mongoVersion;     // (M)  the mongodb version of the pinging mongos
+        std::string _mongoVersion;     // (O)  the mongodb version of the pinging mongos
         bool _isMongoVersionSet;
-        int _configVersion;     // (M)  the config version of the pinging mongos
+        int _configVersion;     // (O)  the config version of the pinging mongos
         bool _isConfigVersionSet;
     };
 
diff --git a/src/mongo/s/type_mongos_test.cpp b/src/mongo/s/type_mongos_test.cpp
index 0d27d057db6..4f2a69e9ccd 100644
--- a/src/mongo/s/type_mongos_test.cpp
+++ b/src/mongo/s/type_mongos_test.cpp
@@ -117,7 +117,9 @@ namespace {
         ASSERT_TRUE(mongos.isWaitingSet());
         ASSERT_FALSE(mongos.isMongoVersionSet());
         ASSERT_TRUE(mongos.isConfigVersionSet());
-        ASSERT_FALSE(mongos.isValid(NULL));
+        /* NOTE: mongoVersion should eventually become mandatory, but is optional now for backward
+         * compatibility reasons */
+        ASSERT_TRUE(mongos.isValid(NULL));
     }
 
     TEST(Validity, MissingConfigVersion) {
@@ -136,7 +138,9 @@ namespace {
         ASSERT_TRUE(mongos.isWaitingSet());
         ASSERT_TRUE(mongos.isMongoVersionSet());
         ASSERT_FALSE(mongos.isConfigVersionSet());
-        ASSERT_FALSE(mongos.isValid(NULL));
+        /* NOTE: configVersion should eventually become mandatory, but is optional now for backward
+         * compatibility reasons */
+        ASSERT_TRUE(mongos.isValid(NULL));
     }
 
     TEST(Validity, Valid) {