SERVER-25741 Disallow collection default collation if featureCompatibilityVersion is 3.2

2 files changed, 27 insertions, 0 deletions

diff --git a/jstests/noPassthrough/collation_feature_compatibility_version.js b/jstests/noPassthrough/collation_feature_compatibility_version.js
index df3516b2b3e..2f393c2a99a 100644
--- a/jstests/noPassthrough/collation_feature_compatibility_version.js
+++ b/jstests/noPassthrough/collation_feature_compatibility_version.js
@@ -29,6 +29,25 @@
     assert.commandWorked(res);
     assert.eq("3.2", res.featureCompatibilityVersion);
 
+    // We cannot create a collection with a default collation when the featureCompatibilityVersion
+    // is 3.2.
+    assert.commandFailed(
+        collationDB.createCollection("collection", {collation: {locale: "fr_CA"}}));
+
+    // We cannot explicitly give a collection the simple collation as its default when the
+    // featureCompatibilityVersion is 3.2.
+    assert.commandFailed(
+        collationDB.createCollection("collection", {collation: {locale: "simple"}}));
+
+    // We cannot create a view with a default collation when the featureCompatibilityVersion is 3.2.
+    assert.commandFailed(collationDB.runCommand(
+        {create: "view", viewOn: "caseInsensitive", collation: {locale: "fr_CA"}}));
+
+    // We cannot explicitly give a view the simple collation as its default when the
+    // featureCompatibilityVersion is 3.2.
+    assert.commandFailed(collationDB.runCommand(
+        {create: "view", viewOn: "caseInsensitive", collation: {locale: "simple"}}));
+
     // All operations reject the collation parameter when the featureCompatibilityVersion is 3.2.
     assert.throws(function() {
         caseInsensitive.aggregate([], {collation: {locale: "en_US"}});
diff --git a/src/mongo/db/catalog/database.cpp b/src/mongo/db/catalog/database.cpp
index feb4111edac..1895acb15f7 100644
--- a/src/mongo/db/catalog/database.cpp
+++ b/src/mongo/db/catalog/database.cpp
@@ -683,6 +683,14 @@ Status userCreateNS(OperationContext* txn,
 
     // Validate the collation, if there is one.
     if (!collectionOptions.collation.isEmpty()) {
+        if (serverGlobalParams.featureCompatibilityVersion.load() ==
+            ServerGlobalParams::FeatureCompatibilityVersion_32) {
+            return Status(ErrorCodes::InvalidOptions,
+                          "The featureCompatibilityVersion must be 3.4 to create a collection or "
+                          "view with a default collation. See "
+                          "http://dochub.mongodb.org/core/3.4-feature-compatibility.");
+        }
+
         auto collator = CollatorFactoryInterface::get(txn->getServiceContext())
                             ->makeFromBSON(collectionOptions.collation);
         if (!collator.isOK()) {