SERVER-36987 ChunkVersion::minorVersion truncates to 16 bit

(cherry picked from commit cf3e9512586e2538833b248895cd14844f5fbd65)

2 files changed, 21 insertions, 8 deletions

diff --git a/src/mongo/s/chunk_version.h b/src/mongo/s/chunk_version.h
index 05517ffb609..54c1ca4f576 100644
--- a/src/mongo/s/chunk_version.h
+++ b/src/mongo/s/chunk_version.h
@@ -59,7 +59,7 @@ public:
 
     ChunkVersion() : _combined(0), _epoch(OID()) {}
 
-    ChunkVersion(int major, int minor, const OID& epoch)
+    ChunkVersion(uint32_t major, uint32_t minor, const OID& epoch)
         : _combined(static_cast<uint64_t>(minor) | (static_cast<uint64_t>(major) << 32)),
           _epoch(epoch) {}
 
@@ -148,12 +148,12 @@ public:
         return _combined > 0;
     }
 
-    int majorVersion() const {
+    uint32_t majorVersion() const {
         return _combined >> 32;
     }
 
-    int minorVersion() const {
-        return _combined & 0xFFFF;
+    uint32_t minorVersion() const {
+        return _combined & 0xFFFFFFFF;
     }
 
     OID epoch() const {
diff --git a/src/mongo/s/chunk_version_test.cpp b/src/mongo/s/chunk_version_test.cpp
index 4bea7f466bd..51c7f9d1cf5 100644
--- a/src/mongo/s/chunk_version_test.cpp
+++ b/src/mongo/s/chunk_version_test.cpp
@@ -28,6 +28,8 @@
 
 #include "mongo/platform/basic.h"
 
+#include <limits>
+
 #include "mongo/db/jsobj.h"
 #include "mongo/s/chunk_version.h"
 #include "mongo/unittest/unittest.h"
@@ -44,16 +46,16 @@ TEST(Parsing, EpochIsOptional) {
     ASSERT(canParse);
     ASSERT(chunkVersionComplete.epoch().isSet());
     ASSERT(chunkVersionComplete.epoch() == oid);
-    ASSERT_EQ(2, chunkVersionComplete.majorVersion());
-    ASSERT_EQ(3, chunkVersionComplete.minorVersion());
+    ASSERT_EQ(2u, chunkVersionComplete.majorVersion());
+    ASSERT_EQ(3u, chunkVersionComplete.minorVersion());
 
     canParse = false;
     ChunkVersion chunkVersionNoEpoch =
         ChunkVersion::fromBSON(BSON("lastmod" << Timestamp(Seconds(3), 4)), "lastmod", &canParse);
     ASSERT(canParse);
     ASSERT(!chunkVersionNoEpoch.epoch().isSet());
-    ASSERT_EQ(3, chunkVersionNoEpoch.majorVersion());
-    ASSERT_EQ(4, chunkVersionNoEpoch.minorVersion());
+    ASSERT_EQ(3u, chunkVersionNoEpoch.majorVersion());
+    ASSERT_EQ(4u, chunkVersionNoEpoch.minorVersion());
 }
 
 TEST(Comparison, StrictEqual) {
@@ -83,5 +85,16 @@ TEST(Comparison, OlderThan) {
     ASSERT(!ChunkVersion(3, 1, epoch).isOlderThan(ChunkVersion(3, 1, epoch)));
 }
 
+TEST(ChunkVersionConstruction, CreateWithLargeValues) {
+    const auto minorVersion = std::numeric_limits<uint32_t>::max();
+    const uint32_t majorVersion = 1 << 24;
+    const auto epoch = OID::gen();
+
+    ChunkVersion version(majorVersion, minorVersion, epoch);
+    ASSERT_EQ(majorVersion, version.majorVersion());
+    ASSERT_EQ(minorVersion, version.minorVersion());
+    ASSERT_EQ(epoch, version.epoch());
+}
+
 }  // unnamed namespace
 }  // namespace mongo