RFR: 8132725: Memory leak in Arguments::add_property function

[Dmitry Dmitriev]

Hello,

Please review this fix which remove memory leak in 
Arguments::add_property function. Also, I need a sponsor for this fix, 
who can push it.

Arguments::add_property function allocate memory for key and value. Then 
key and values are passed to the PropertyList_unique_add function which 
use SystemProperty class to add or update property value. SystemProperty 
class maintains it's own copy of key and value and thus copy passed key 
and value. Therefore key and value must be freed in add_property 
function(with exception for value in case of "java.vendor.url.bug" and 
"sun.java.command" properties).

In this fix I allocate memory only for key when passed property contains 
value. If passed property not contains value, then I not allocate memory 
for key and use passed property string. Value also extracted from passed 
property string instead of allocating. To accomplish that I changed 
declaration of "value" in several functions from "char *" to  "const 
char *" since value is not modified in these functions(PropertyList_* 
functions, SystemProperty class methods).

Processing of "java.vendor.url.bug" and "sun.java.command" properties 
also corrected. Now when these properties redefined, then code checks if 
memory was allocated for special variables of these properties(checking 
that not contains default value) and free it.

Webrev: http://cr.openjdk.java.net/~ddmitriev/8132725/webrev.00/ 
<http://cr.openjdk.java.net/%7Eddmitriev/8132725/webrev.00/>
JBS: https://bugs.openjdk.java.net/browse/JDK-8132725
Tested: JPRT(hotspot test set), hotspot all, vm.quick

Thanks,
Dmitry