Check result of u_parse_query

u_parse_query starts with strtok_r(src, "&,", &pp) thus these filters
will be two tokens. As the second one does not contain an equal sign,
u_parse_query returns NULL, and hash_scan_begin tries to use it
without any checks.

The problem is with the comma in the filter, and I could not find a
way to circumvent it. As these minimal examples demonstrates:
wsman enumerate 'foo' --dialect "http://schemas.dmtf.org/wbem/wsman/1/wsman/SelectorFilter" --filter 'foo="bar,foo"'
wsman enumerate 'foo' --dialect "http://schemas.dmtf.org/wbem/wsman/1/wsman/SelectorFilter" --filter "foo='bar,foo'"

Reported by Zoltan Micskei <zoltan.micskei@mit.bme.hu>
1 file changed