Bug #22079: Float#ceil gives incorrect result

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.7 (2025-01-15 revision be31f993d7) [x86_64-linux]
• Backport: 3.3: REQUIRED, 3.4: DONE, 4.0: DONE

[cryptogopher (crypto gopher)]

Let's take following number as an example:

> Float::MIN
=> 2.2250738585072014e-308

This gives proper result:

> Float::MIN.ceil(308)
=> 2.9999999999999997e-308

But this does not:

> Float::MIN.floor(309)
=> NaN

even though the result is perfectly valid Float number:

> "2.3e-308".to_f
=> 2.3e-308

[nobu (Nobuyoshi Nakada)]

• Backport changed from 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN to 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED

GH-17097

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|09dacb9c3d61264f3eb3731e2c65feb869130228.

---

[Bug #22079] Fix Float#ceil and Float#floor edge cases

[luke-gru (Luke Gruber)]

• Backport changed from 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED to 3.3: REQUIRED, 3.4: REQUIRED, 4.0: DONE

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 3.3: REQUIRED, 3.4: REQUIRED, 4.0: DONE to 3.3: REQUIRED, 3.4: DONE, 4.0: DONE

ruby_3_4 bc5e9ac4cf2f416435c8aac778ba272ac0205d5a merged revision(s) 97ec327efc74b0df42421fa4344d1f05452d0623, 09dacb9c3d61264f3eb3731e2c65feb869130228.