Author: wikimedia-bugreports
Description:
See for example http://de.wikinews.org/w/api.php?action=query&prop=info&titles=Hauptseite&format=yaml compared to http://de.wikinews.org/w/api.php?action=query&prop=info&titles=Hauptseite
Both the namespace (ns) and the counter variable are numerical zero but in the yaml output the value is just empty.
Version: 1.12.x
Severity: normal
Upon seeing this bug, my first instinct was that PHP's weak type system was to blame, and that someone had done $var == '' somewhere (which is true if $var is '0'). It turned out there was a == '' in the YAML formatter, but that didn't cause the bug. It was plain, old-fashioned, non-PHP-related stupidity in the form of if($value), which was probably intended to be false for null and empty strings, but is also false for 0 and '0'.
Fixed in r40384.