Backport #9575: Step with 0 step is buggy

• Status: Closed
• Assignee: naruse (Yui NARUSE)

[marcandre (Marc-Andre Lafortune)]

I didn't realize that we now allow stepping with a '0' step. It should probably have been mentioned in the NEWS of 2.1.0?

Anyways, couple of bugs with that new feature:

bn = 1 << 100
bn.step(by: 0, to: bn).first(2) # => [bn, bn] ok
bn.step(by: 0).first(2)         # => [bn.to_f, bn.to_f] not ok
bn.step(by: 0, to: 0).first(2)  # => [] not ok

The corresponding size don't all work either:

bn.step(by: 0) # => Float::INFINITY, ok
bn.step(by: 0, to: bn).size # => ZeroDivisionError: divided by 0, should be infinity
bn.step(by: 0, to: 0).size  # => same
1.step(by:0, to: 42).size   # => same

My patch is almost finished.

[marcandre (Marc-Andre Lafortune)]

Found many other problems when some arguments are floats:

4.2.step(by: 0.0).first(2)           # => [], should be [4.2, 4.2]
4.2.step(by: -0.0).first(2)          # => [-Infinity, -Infinity], should be [4.2, 4.2]
42.step(by: 0, to: -Float::INFINITY).first(2) # => [], should be [42, 42]
42.step(by: 0, to: 42.5).first(2)    # => [42.0, 42.0], should really be [42, 42]

I believe I've fixed all cases.

[marcandre (Marc-Andre Lafortune)]

• Tracker changed from Bug to Backport
• Project changed from Ruby master to Backport21
• Category deleted (core)
• Assignee changed from marcandre (Marc-Andre Lafortune) to naruse (Yui NARUSE)
• Target version deleted (2.2.0)

You'll have to backport r45206 -> r45208 in addition to r45209.

[marcandre (Marc-Andre Lafortune)]

Also, it might be good to modify the 2.1 NEWS file to mention possibility of 0 step.
Thanks

[naruse (Yui NARUSE)]

• Status changed from Open to Feedback

r45209 conflicts with current ruby_2_1 branch.

Marc-Andre Lafortune wrote:

Also, it might be good to modify the 2.1 NEWS file to mention possibility of 0 step.
Thanks

yeah, could you add NEWS and additional previous commits and NEWS commit?

thanks

[marcandre (Marc-Andre Lafortune)]

• Status changed from Feedback to Open

Yui NARUSE wrote:

r45209 conflicts with current ruby_2_1 branch.

Right, #9570 must be backported first.

More explicitly, the following will backport both without conflicts:

git cherry-pick c1fc20124c
git cherry-pick e184e31c0956..1636c60fe16

yeah, could you add NEWS and additional previous commits and NEWS commit?

I pushed r45234 (ec8de033e72935)

I hope that's what you wanted?

[nagachika (Tomoyuki Chikanaga)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r46401.

---

merge revision(s) r45207,r45208,r45209,r45210: [Backport #9575]

* numeric.c: Create var for rb_intern("<=>")
* numeric.c: Fix Numeric#step with 0 unit [Bug #9575]