On Wed, 14 Jan 2026 03:22:33 GMT, Ioi Lam <[email protected]> wrote:
>> The bug is here on line 121:
>>
>> https://github.com/openjdk/jdk/blob/586846b84a38d285c5905437e903cfc57f609410/src/java.base/windows/classes/java/lang/ProcessImpl.java#L118-L121
>>
>> If `System.out` has been closed, `fdAccess.getHandle()` will return -1. This
>> causes `stdHandles[1]` to have the same value as if the child process's
>> stdout was redirected with `Redirect.PIPE`. This will cause a Pipe to be
>> created here for the child process's STDOUT on line 168:
>>
>> https://github.com/openjdk/jdk/blob/586846b84a38d285c5905437e903cfc57f609410/src/java.base/windows/native/libjava/ProcessImpl_md.c#L158-L184
>>
>> However, the caller of the `ProcessBuilder` is not aware of this and will
>> not drain this pipe. This causes the child process to get stuck when writing
>> to its stdout when the pipe 's buffer is filled up.
>>
>> The fix is to treat the redirection as `Redirect.DISCARD` when `System.out`
>> and/or `System.err` have been closed.
>
> Ioi Lam has updated the pull request incrementally with one additional commit
> since the last revision:
>
> Review comments from @RogerRiggs
src/java.base/windows/classes/java/lang/ProcessImpl.java line 133:
> 131: if (stdHandles[1] == -1L) {
> 132: // FileDescriptor.out has been closed.
> 133: f1 = setFileOutput(Redirect.DISCARD, stdHandles,
> 1);
More compact yes, but I prefer to update local state inline, its easier to see
the consistent pattern of state updates across the different cases.
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PR Review Comment: https://git.openjdk.org/jdk/pull/29198#discussion_r2690701865
