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| author | lit <litlighilit@foxmail.com> | 2024-04-03 15:32:26 +0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-04-03 09:32:26 +0200 |
| commit | dee55f587f4e3cfc8ffe28e4a41eba9c8ed7f2f8 (patch) | |
| tree | 587368a63884e2e69dce68b472839c9b605303f5 /lib/std | |
| parent | 3bdb531f90c3d804c0f8d25865955120b9598b13 (diff) | |
| download | Nim-dee55f587f4e3cfc8ffe28e4a41eba9c8ed7f2f8.tar.gz | |
Update syncio.nim, fixes "open by FileHandle" doesn't work on Windows (#23456)
## Reprodution if on Windows: ```Nim when defined(windows): var file: File let succ = file.open(<aFileHandle>) ``` then `succ` will be false. If tested, it can be found to fail with errno `22` and message: `Invalid argument` ## Problem After some investigations and tests, I found it's due to the `mode` argument for `fdopen`. Currently `NoInheritFlag`(`'N'` in Windows) is added to `mode` arg passed to `_fdopen`, but if referring to [Windows `_fdopen` doc](https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/fdopen-wfdopen?view=msvc-170), you'll find there is no `'N'` describled. That's `'N'` is not accepted by `_fdopen`. Therefore, the demo above will fail. ## In Addition To begin with, technologically speaking, when opening with a `fileHandle`(or called `fd`), there is no concept of fd-inheritable as `fd` is opened already. In POSIX, `NoInheritFlag` is defined as `e`. It's pointed out in [POSIX `open` man-doc](https://www.man7.org/linux/man-pages/man3/fopen.3.html) that `e` in mode is ignored for fdopen(), which means `e` for `fdopen()` is not wanted, just allowed. Therefore, better to also not pass `e` to `fdopen` --- In all, that's this PR.
Diffstat (limited to 'lib/std')
| -rw-r--r-- | lib/std/syncio.nim | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/std/syncio.nim b/lib/std/syncio.nim index 44244297f..2b39375ea 100644 --- a/lib/std/syncio.nim +++ b/lib/std/syncio.nim @@ -648,6 +648,9 @@ const "" else: "" + RawFormatOpen: array[FileMode, cstring] = [ + # used for open by FileHandle, which calls `fdopen` + cstring("rb"), "wb", "w+b", "r+b", "ab"] FormatOpen: array[FileMode, cstring] = [ cstring("rb" & NoInheritFlag), "wb" & NoInheritFlag, "w+b" & NoInheritFlag, "r+b" & NoInheritFlag, "ab" & NoInheritFlag @@ -749,7 +752,7 @@ proc open*(f: var File, filehandle: FileHandle, filehandle) else: filehandle if not setInheritable(oshandle, false): return false - f = c_fdopen(filehandle, FormatOpen[mode]) + f = c_fdopen(filehandle, RawFormatOpen[mode]) result = f != nil proc open*(filename: string, |