Bug #15932: wrong "void value expression" error for 'next' or 'break' statements inside an 'if' assignment

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 1.8.7, 2.7.0preview1
• Backport: 2.4: REQUIRED, 2.5: DONE, 2.6: REQUIRED

[cvss (Kirill Vechera)]

When a 'next' or 'break' statement for block/loop control is placed inside an 'if' assignment, the parser outputs an error "void value expression". The same parsing error raises for the ternary operator in the same conditions.

I think, the the correct behavior should be consistent with the behavior of the 'case' statement, that is parsing such a code without errors and leaving the right-side variable with 'nil' value.

Examples of code giving a "void value expression" error:

begin
	a = if false
		'A'
	else
		next
	end
end while false

begin
	a = false ? 'A' : next
end while false

Example of code running without errors:

begin
	a = case false
		when true
			'A'
		else
			next
		end
end while false

begin
	a = (false or next)
end while false

[cvss (Kirill Vechera)]

• ruby -v changed from 1.8.7 .. 2.7.0preview1 to 1.8.7, 2.7.0preview1

[nobu (Nobuyoshi Nakada)]

• Backport changed from 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN to 2.4: REQUIRED, 2.5: REQUIRED, 2.6: REQUIRED

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|01b3a3804334be19d013526d3edde2b84399ae43.

---

Fix wrong "void value expression" error

• parse.y (value_expr_check): if either of then or else
  statements is not a void value expression, the whole if is not
  also a void value expression. [Bug #15932]

[jeremyevans0 (Jeremy Evans)]

• Related to Bug #11143: it should always be possible to return from an if added

[usa (Usaku NAKAMURA)]

• Backport changed from 2.4: REQUIRED, 2.5: REQUIRED, 2.6: REQUIRED to 2.4: REQUIRED, 2.5: DONE, 2.6: REQUIRED

Backported into ruby_2_6 at r67903.