I have nearly completed the task of overhauling my web app to be properly "UTF-8 aware". I have found, though, that if I set the connection character set to utf8 using mysqli_set_charset, the result is that output appears incorrectly (indeed it appears as though the page's character encoding had been misidentified), whereas if I do not set the connection character set, it appears correctly.
For example, a string stored in one table in my database - the column's character set is utf8 - is echoed properly as Página principal if I do not set the connection character set. If I do set the connection character set, it appears as Página principal.
Details: The PHP scripts I am using to test this behaviour have the following meta tag in the <head> section:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
I have determined that the default character set for new connections on my host is latin1. The database I am connecting to has default character set utf8. Here is the code used to create the database link:
$cxn = @mysqli_connect('localhost', $db_user, $db_password, $db_database) or die('Failed to connect to the database.');
mysqli_set_charset($cxn, 'utf8');
mysqli_query($cxn, 'SET SESSION sql_mode = \'TRADITIONAL\'');
Additionally: In case it should serve as some extra forensic evidence, I have found that if I view the page in Firefox and manually change the character encoding to ISO-8859-1, the aforementioned string appears as Página principal.