filemerge: make capability check for internal tools ignore merge-tools section
This is follow up of
4d7b11877dd0.
Before this patch, capability check of internal merge tools falls back
to _toolbool(), which examines configurations in "merge-tools" section.
But "hg help config" explicitly says that "merge-tools" section
configures external merge tools.
Therefore, this patch makes capability check for internal tools in
hascapability() always ignore configurations in merge-tools section.
In this patch, command line configurations below are added at tests in
tests/test-merge-tools.t, in order to confirm that explicit
configuration is intentionally ignored at tool selection.
--config merge-tools.:INTERNAL_TOOL.CAPABILITY=true
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}