Issue #19245 has been updated by nobu (Nobuyoshi Nakada). byroot (Jean Boussier) wrote:
This is specified:
Note that “ruby-spec” is not the specification of ruby. The word “specified” makes confusion.
### Possible solutions
We could have a strict version of `pack`, either `pack(template, strict: true)` or `pack!(template)`.
Usually we don’t add `!` for stricter behavior. ---------------------------------------- Feature #19245: Strict mode for Array#pack that doesn't silently truncate numbers that are too large for the given directive https://bugs.ruby-lang.org/issues/19245#change-100716 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ```ruby
[256].pack("C").unpack1("C") => 0 [257].pack("C").unpack1("C") => 1
This is specified:
```ruby
it "encodes the least significant 32 bits of a negative number" do
[ [[-0x0000_0021], "\xdf\xff\xff\xff"],
[[-0x0000_4321], "\xdf\xbc\xff\xff"],
[[-0x0065_4321], "\xdf\xbc\x9a\xff"],
[[-0x7865_4321], "\xdf\xbc\x9a\x87"]
].should be_computed_by(:pack, pack_format())
end
But not documented in `Array#pack`. I think that in many case this may lead to silent bugs. ### Possible solutions We could have a strict version of `pack`, either `pack(template, strict: true)` or `pack!(template)`. Or alternatively if we think this is never a desired behavior, we could change `pack` to first warn on truncation and later raise. -- https://bugs.ruby-lang.org/