As shown in https://github.com/nodejs/node/issues/9096, the offset and
end value of the `slice` call are coerced to numbers and then passed to
`FastBuffer`, which internally truncates the mantissa part if the number
is actually a floating point number. This actually affects the new
length of the slice calculation. For example,
> const original = Buffer.from('abcd');
undefined
> original.slice(original.length / 3).toString()
'bc'
This happens because, starting value of the slice is 4 / 3, which is
1.33 (approximately). Now, the length of the slice is calculated as
the difference between the actual length of the buffer and the starting
offset. So, it becomes 2.67 (4 - 1.33). Now, a new `FastBuffer` is
constructed, with the following values as parameters,
1. actual buffer object,
2. starting value, which is 1.33 and
3. the length 2.67.
The underlying C++ code truncates the numbers and they become 1 and 2.
That is why the result is just `bc`.
This patch makes sure that all the offsets are coerced to integers
before any calculations are done.
Fixes: https://github.com/nodejs/node/issues/9096
PR-URL: https://github.com/nodejs/node/pull/9101
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
With V8 4.4 removing the external array data API currently used by
Buffer, the new implementation uses the Uint8Array to back Buffer.
Buffers now have a maximum size of Smi::kMaxLength, as defined by V8.
Which is ~2 GB on 64 bit and ~1 GB on 32 bit.
The flag --use-old-buffer allows using the old Buffer implementation.
This flag will be removed once V8 4.4 has landed.
The two JS Buffer implementations have been split into two files for
simplicity.
Use getter to return expected .parent/.offset values for backwards
compatibility.
PR-URL: https://github.com/nodejs/io.js/pull/1825
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Enable linting for the test directory. A number of changes was made so
all tests conform the current rules used by lib and src directories. The
only exception for tests is that unreachable (dead) code is allowed.
test-fs-non-number-arguments-throw had to be excluded from the changes
because of a weird issue on Windows CI.
PR-URL: https://github.com/nodejs/io.js/pull/1721
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
The copyright and license notice is already in the LICENSE file. There
is no justifiable reason to also require that it be included in every
file, since the individual files are not individually distributed except
as part of the entire package.
Sakthipriyan Vairamani (thefourtheye)