Backport #3297
closed[patch] Array#pack("i_") is broken in big endian 64bit systems
Description
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See also http://redmine.ruby-lang.org/issues/show/1131 for a similar issue (String#unpack("V"))
Array#pack("i_") is broken in big endian 64 bit systems
irb> [1].pack("i_")
=> "\000\000\000\000"
The root cause is similar to the one of issue 1131, use of a wrong offset in a 64bit long.
But the fix is a bit simpler and is probably correct for all other architectures too.
According to the documentation, the "i" format of pack/unpack uses a fixed-size (32bit) integer, while adding "_" uses the system-size.
However, the implementation of Array#pack uses a 'long' type (64bit !) to store an intermediate value, thus breaking OFF() in accessing the wrong 4 bytes of the value.
Fix: Use 'int' to store the intermediate value (use of int is correct for the fixed-size as well as the system-size case) and don't use OFF()
With this patch, the pack_spec and unpack_spec tests of rubyspec.org run without issues.
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Files
Updated by akr (Akira Tanaka) over 14 years ago
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OFF* macros are already removed from Ruby 1.8.8.
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Updated by shyouhei (Shyouhei Urabe) over 13 years ago
- Status changed from Open to Feedback
Sorry for this late reply, does this still happen? I guess it has already been fixed for a while.
Updated by jeremyevans0 (Jeremy Evans) about 5 years ago
- Status changed from Feedback to Closed