Optimize empty string assignment

Author: adazem009

src/scratch/string_functions.cpp

@@ -35,13 +35,6 @@ extern "C"
     /*! Assigns the given string to str. */
     void string_assign(StringPtr *str, const StringPtr *another)
     {
-        if (another->size == 0) {
-            str->size = 0;
-            string_alloc(str, 0);
-            str->data[0] = u'\0';
-            return;
-        }
-
         string_alloc(str, another->size);
         str->size = another->size;
         memcpy(str->data, another->data, (another->size + 1) * sizeof(typeof(*str->data)));

test/scratch_classes/string_functions_test.cpp

@@ -69,4 +69,23 @@ TEST(StringFunctionsTest, AssignAlloc)
     ASSERT_TRUE(str2.data);
     ASSERT_NE(str2.data, str1.data);
     ASSERT_EQ(memcmp(str2.data, str1.data, (str2.size + 1) * sizeof(typeof(*str2.data))), 0);
+
+    string_assign_cstring(&str2, "");
+    ASSERT_EQ(str2.size, 0);
+    ASSERT_GE(str2.allocatedSize, 1);
+    ASSERT_TRUE(str2.data);
+    ASSERT_EQ(str2.data[0], u'\0');
+
+    string_assign_cstring(&str2, "test");
+    string_assign_cstring(&str2, nullptr);
+    ASSERT_EQ(str2.size, 0);
+    ASSERT_GE(str2.allocatedSize, 1);
+    ASSERT_TRUE(str2.data);
+    ASSERT_EQ(str2.data[0], u'\0');
+
+    string_assign(&str1, &str2);
+    ASSERT_EQ(str1.size, 0);
+    ASSERT_GE(str1.allocatedSize, 1);
+    ASSERT_TRUE(str1.data);
+    ASSERT_EQ(str1.data[0], u'\0');
 }