fix

src/utils/blob.h

@@ -109,15 +109,9 @@ class blob
     /// NOTE: this operation is not efficient since it involves a memory copy.
     [[nodiscard]] static blob create_from_bytes(const char *s, size_t len)
     {
-        if (s == nullptr) {
-            // TODO(wangdan): decide if an empty blob could be returned, which is initialized
-            // by default constructor blob() whose length is zero and all pointers(_holder,
-            // _buffer and _data) are null.
-            CHECK_EQ_MSG(len,
-                         0,
-                         "null source pointer with non-zero length would lead to "
-                         "undefined behaviour");
-        }
+        DCHECK(s != nullptr || len == 0,
+               "null source pointer with non-zero length would lead to "
+               "undefined behaviour");
 
         std::shared_ptr<char> s_arr(new char[len], std::default_delete<char[]>());
         memcpy(s_arr.get(), s, len);

src/utils/test/blob_test.cpp

@@ -24,16 +24,25 @@
 
 namespace dsn {
 
-TEST(BlobTest, CreateFromNullptr)
+TEST(BlobTest, CreateFromZeroLengthNullptr)
 {
     const auto &obj = blob::create_from_bytes(nullptr, 0);
 
-    // TODO(wangdan): once create_from_bytes() could return an empty blob, add case
-    // to test if all pointers are null.
     EXPECT_EQ(0, obj.length());
     EXPECT_EQ(0, obj.size());
 }
 
+#ifndef NDEBUG
+
+TEST(BlobTest, CreateFromNonZeroLengthNullptr)
+{
+    ASSERT_DEATH({ const auto &obj = blob::create_from_bytes(nullptr, 1); },
+                 "null source pointer with non-zero length would lead to "
+                 "undefined behaviour");
+}
+
+#endif
+
 struct blob_base_case
 {
     std::string expected_str;