I've seen [Blockquote rewrap destroys code](https://meta.stackexchange.com/q/171197/), but that question (and answer) are about the situation where a user mistakenly uses the quote button instead of the code button.

I instead want to use *both*.  For example, I might want to quote code from another source (often from the question).  If I have some code explicitly enclosed in triple-backticks:

    ```c
    int main(void) {
        printf("Hello world!\n");
    }
    ```

then selecting that and pressing the quote button gives me:

    > ```c int main(void) {
    >     printf("Hello world!\n"); } ```

I cannot imagine that this is deliberate.  I claim that text in triple-backticks should be left alone, and each line instead should just be prefixed with `> `.

Update:

Trying [the Stacks editor](https://meta.stackexchange.com/questions/360033/opt-in-alpha-test-for-a-new-stacks-editor) in Markdown mode, I seem to get an even worse monstrosity:

     > ```c> c> int main(void) { > {> printf("Hello world!\n");)> ;> }
     > ````>