Rollup merge of #103360 - ChrisDenton:isterm-filetype, r=thomcc

Reduce false positives in msys2 detection

Currently msys2 will be detected by getting the file path and looking to see if it contains the substrings "msys-" and "-ptr" (or "cygwin-" and "-pty"). This risks false positives, especially with filesystem files and if `GetFileInformationByHandleEx` returns a [full path](https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/nf-ntifs-ntqueryinformationfile#remarks).

This PR adds a check to see if the handle is a pipe before doing the substring search. Additionally, for "msys2-" or "cygwin-" it only checks if the file name starts with the substring rather than looking at the whole path.

library/std/src/sys/windows/c.rs

@@ -129,6 +129,8 @@ pub const FIONBIO: c_ulong = 0x8004667e;
 
 pub const MAX_PATH: usize = 260;
 
+pub const FILE_TYPE_PIPE: u32 = 3;
+
 #[repr(C)]
 #[derive(Copy)]
 pub struct WIN32_FIND_DATAW {
@@ -1114,6 +1116,7 @@ extern "system" {
  lpFileInformation: LPVOID,
  dwBufferSize: DWORD,
  ) -> BOOL;
+ pub fn GetFileType(hfile: HANDLE) -> DWORD;
  pub fn SleepConditionVariableSRW(
  ConditionVariable: PCONDITION_VARIABLE,
  SRWLock: PSRWLOCK,

library/std/src/sys/windows/io.rs

@@ -120,6 +120,11 @@ unsafe fn handle_is_console(handle: BorrowedHandle<'_>) -> bool {
 }
 
 unsafe fn msys_tty_on(handle: c::HANDLE) -> bool {
+ // Early return if the handle is not a pipe.
+ if c::GetFileType(handle) != c::FILE_TYPE_PIPE {
+ return false;
+ }
+
  const SIZE: usize = size_of::<c::FILE_NAME_INFO>() + c::MAX_PATH * size_of::<c::WCHAR>();
  let mut name_info_bytes = Align8([0u8; SIZE]);
  let res = c::GetFileInformationByHandleEx(
@@ -137,11 +142,13 @@ unsafe fn msys_tty_on(handle: c::HANDLE) -> bool {
  let name_ptr = name_info_bytes.0.as_ptr().offset(size_of::<c::DWORD>() as isize).cast::<u16>();
  let s = core::slice::from_raw_parts(name_ptr, name_len);
  let name = String::from_utf16_lossy(s);
+ // Get the file name only.
+ let name = name.rsplit('\\').next().unwrap_or(&name);
  // This checks whether 'pty' exists in the file name, which indicates that
  // a pseudo-terminal is attached. To mitigate against false positives
  // (e.g., an actual file name that contains 'pty'), we also require that
- // either the strings 'msys-' or 'cygwin-' are in the file name as well.)
- let is_msys = name.contains("msys-") || name.contains("cygwin-");
+ // the file name begins with either the strings 'msys-' or 'cygwin-'.)
+ let is_msys = name.starts_with("msys-") || name.starts_with("cygwin-");
  let is_pty = name.contains("-pty");
  is_msys && is_pty
 }