Problem

In eval_dict(), the dictionary d is allocated when evaluate is true (lines 958–963):

if (evaluate)
{
    d = dict_alloc();
    if (d == NULL)
        return FAIL;
}

Later, when parsing a Vim9 dictionary key written in bracket form ([key]), the code reports an error if the closing ] is missing and returns early (lines 993–998):

if (**arg != ']')
{
    emsg(_(e_missing_matching_bracket_after_dict_key));
    clear_tv(&tvkey);
    return FAIL;
}

Returning directly bypasses the shared cleanup in the failret: block, where d is freed. This results in a memory leak on this error path.

Solution

Replace the direct return FAIL; with goto failret; so that the existing cleanup logic is executed. The fix is included in this commit.