SERVER-32641 uassert, not dassert, for too many KeyString type bits

2 files changed, 21 insertions, 1 deletions

diff --git a/src/mongo/db/storage/key_string.h b/src/mongo/db/storage/key_string.h
index 6f7a6baebf2..c0857ca3180 100644
--- a/src/mongo/db/storage/key_string.h
+++ b/src/mongo/db/storage/key_string.h
@@ -40,6 +40,7 @@
 #include "mongo/bson/timestamp.h"
 #include "mongo/db/record_id.h"
 #include "mongo/platform/decimal128.h"
+#include "mongo/util/assert_util.h"
 
 namespace mongo {
 
@@ -246,7 +247,9 @@ public:
             return _buf[0] & 0x7f;
         }
         void setSizeByte(uint8_t size) {
-            dassert(size < kMaxBytesNeeded);
+            // This error can only occur in cases where the key is not only too long, but also
+            // has too many fields requiring type bits.
+            uassert(ErrorCodes::KeyTooLong, "The key is too long", size < kMaxBytesNeeded);
             _buf[0] = 0x80 | size;
         }
 
diff --git a/src/mongo/db/storage/key_string_test.cpp b/src/mongo/db/storage/key_string_test.cpp
index 3f9530a8bcc..8efd5ff7197 100644
--- a/src/mongo/db/storage/key_string_test.cpp
+++ b/src/mongo/db/storage/key_string_test.cpp
@@ -1161,6 +1161,23 @@ TEST_F(KeyStringTest, RecordIds) {
     }
 }
 
+TEST_F(KeyStringTest, KeyWithTooManyTypeBitsCausesUassert) {
+    BSONObj obj;
+    {
+        BSONObjBuilder builder;
+        {
+            BSONArrayBuilder array(builder.subarrayStart("x"));
+            auto zero = BSON("" << 0.0);
+            for (int i = 0; i < 1016; i++)
+                array.append(zero.firstElement());
+        }
+
+        obj = builder.obj();
+    }
+    KeyString key(version);
+    ASSERT_THROWS_CODE(key.resetToKey(obj, ONE_ASCENDING), DBException, ErrorCodes::KeyTooLong);
+}
+
 namespace {
 const uint64_t kMinPerfMicros = 20 * 1000;
 const uint64_t kMinPerfSamples = 50 * 1000;