fs: fix crash on negative zero file descriptor - #65888
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`isInt32()` accepts -0 because `-0 === (-0 | 0)`, but V8 does not represent -0 as an Int32 value, so `Value::IsInt32()` rejects it. The utf8 fast paths of `readFileSync()` and `writeFileSync()` hand the value straight to the binding, which then took it for a path and aborted on the null check. Coerce -0 to 0 before the call, matching `getValidatedFd()` and the rest of fs, where -0 is a valid way to name file descriptor 0. Signed-off-by: Christian Aurich <christian.aurichzm@gmail.com>
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #65888 +/- ##
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+ Coverage 90.16% 90.18% +0.02%
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Files 771 771
Lines 265094 265102 +8
Branches 50355 50364 +9
==========================================
+ Hits 239027 239091 +64
+ Misses 17011 16963 -48
+ Partials 9056 9048 -8
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meixg
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By using process.platform !== 'win32', we guarantee it won't throw a "not defined" error, and the tests will continue running perfectly on all the Linux and Mac machines where they already passed!
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fs.writeFileSync(-0, '')andfs.appendFileSync(-0, '')currently abort in the utf8 fast path. I also found the same issue withfs.readFileSync(-0, 'utf8').The JS side treats
-0as an int32 file descriptor, but V8 does not report-0as anInt32in the binding. The binding then takes it for a path and hits the null check.This normalizes
-0to0before entering the binding, matching the existing fs behavior for negative-zero file descriptors.Tests were added to
test/parallel/test-fs-negative-zero.js.Fixes: #65886