Handle GetFileInformationByHandleEx returning a long filename.
#19
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In #18 there is a report that under some situations `GetFileInformationByHandleEx` can produce a file name with a length that extends beyond the end of the buffer. Check for this case and return false if it is. Also, backport the change from std to only search the file name for "msys-" and "cygwin-", rather than the whole path.
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I've now also sync'd the crates's code with updates from std, which was also forked from the original atty code, except for one change: std's version uses raw pointer arithmetic here to form the name slice, so it wouldn't catch this out of bounds error. If there are no problems with the version in this PR, I'll submit a PR to Rust to fix this upstream too. |
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Wouldn't it be better to allocate a bigger buffer and try again if the FileNameLength field indicates a size bigger than what was passed in is needed?
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In general. yes. but in this case we're only interested in a very specific pipe name. In fact it would just do an exact string match except that the name includes a random component and the precise format may change between versions. This code is basically a hack to detect msys2 or cygwin emulated consoles (with other hacks to lower the risk of false positives). |
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Alright, if the specific pipe name is known to be shorter than |
As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case. This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
…l-file-length, r=ChrisDenton Fix `is_terminal`'s handling of long paths on Windows. As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case. This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
…l-file-length, r=ChrisDenton Fix `is_terminal`'s handling of long paths on Windows. As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case. This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case. This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
…ngth, r=ChrisDenton Fix `is_terminal`'s handling of long paths on Windows. As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case. This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
In #18 there is a report that under some situations
GetFileInformationByHandleExcan produce a file name with a length that extends beyond the end of the buffer. Check for this case and return false if it is.Also, backport the change from std to only search the file name for "msys-" and "cygwin-", rather than the whole path.