Description:
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whenever mysql_select_db returns false PHP should output a warning message to the browser if php is configured to do so. As it stands now when mysql_select_db fails, PHP generates no warning on failure. This is not consistent with other PHP mysql_* functions.

Reproduce code:
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Make sure all warnings are enabled in php.ini

psuedo code:

$connection = mysql_connect( "host", "user", "pass" );

mysql_select_db( "some non existent DB", $connection );

mysql_select_db should return false, but no warning is generated

Expected result:
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a warning should be outputed to the browser

Actual result:
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function returns correctly, but no warning is outputted