realText generates string with broken last character in some cases

[apotheosis91]

When realText generates a string that ends with some specific character (for example, р (U+0440) in ru_RU or uk_UA locale; є (U+0454) in uk_UA locale) this character becomes broken.
And when I trying to insert generated string into mysql database I get an error:
SQLSTATE[HY000]: General error: 1366 Incorrect string value: '\xD1.'

Here is how to reproduce it:

$faker = Faker\Factory::create('ru_RU');
$faker->seed(208);
$title = $faker->realText(32);  // returns 'Какой-то этакой характе<broken_char_here>.'

Looks like this happens because of rtrim($text, ',— ') in appendEnd method.
Em dash — is not an ASCII character so it can cause problems there.

rtrim doesn't understand — as one character, but 3 bytes (E2 80 94) and it will trim any of those bytes individually.
So, when text ends with р character (it has hex representation D1 80) rtrim cuts 'half a char' from it: D180 and it becomes broken.

I think changing rtrim to preg_replace will solve the issue.

[fzaninotto]

I believe it's because of utf-8 handling. rtrim isn't utf8-safe.