IMAP Protocol Desynchronization and Response Smuggling via Naive Literal Parsing

`libcurl` incorrectly parses IMAP literals (`{size}`) even when they are embedded within quoted strings (e.g., email subjects or headers). This behavior violates **RFC 3501**, which mandates that content inside double quotes must be treated as opaque text.

/* Pseudocode representation of the flaw */
ptr = memchr(line, '{', len);
if(ptr) {
    /* Logic proceeds to parse number inside {} without checking if inside quotes */
}