Global being masked by local function argument with the same name

[HenrikBengtsson]

From futureverse/doFuture#46:

findGlobals() properly identifies b as a global in:

> globals::findGlobals({ f <- function(a=0) { a }; f(b) }, substitute = TRUE)
[1] "{"     "<-"    "b"

but it fails to identify a as a global in:

> globals::findGlobals({ f <- function(a=0) { a }; f(a) }, substitute = TRUE)
[1] "{"  "<-"

[HenrikBengtsson]

The use of argument a inside that local function is critical. If we drop it, a is properly identified as a global;

> globals::findGlobals({ f <- function(a=0) { a }; f(a) }, substitute = TRUE)
[1] "{"  "<-"

and

> globals::findGlobals({ f <- function(a=0) { }; f(a) }, substitute = TRUE)
[1] "{"  "<-" "a"

Also, the call to f() is irrelevant, so we can simplify further as:

> globals::findGlobals({ function(a) a; a }, substitute = TRUE)
[1] "{"

and

> globals::findGlobals({ function(a) NULL; a }, substitute = TRUE)
[1] "{" "a"

[HenrikBengtsson]

Related to #61 It's not

[HenrikBengtsson]

Fixed in develop branch.