在 2025-12-29 02:00, Pali Rohár 写道:
If the GetEnvironmentVariable was called with NULL buffer then the return value is buffer size including its terminating null character.This differs from the case when GetEnvironmentVariable succeeds, then it returns size without the terminating null character. CRT getenv_s function always returns size with terminating null character. --- mingw-w64-libraries/winstorecompat/src/getenv_s.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mingw-w64-libraries/winstorecompat/src/getenv_s.c b/mingw-w64-libraries/winstorecompat/src/getenv_s.c index ed7c52523279..5988082fab32 100644 --- a/mingw-w64-libraries/winstorecompat/src/getenv_s.c +++ b/mingw-w64-libraries/winstorecompat/src/getenv_s.c @@ -63,6 +63,13 @@ errno_t __cdecl getenv_s(size_t *pReturnValue, char *dstBuf, rsize_t dstSize, co if (dstBuf) dstBuf[0] = '\0'; return ERANGE; + } else if (dstSize == 0) { + /* If the GetEnvironmentVariable was called with NULL buffer then + * the return value is same as above case: buffer size including its + * terminating null character. + */ + *pReturnValue = ret; + return 0;
This comment says 'NULL buffer', but `dstBuf` is a parameter so it's unclear that whether it's null or not. `GetEnvironmentVariableA()` accepts a length of zero with either a null or non-null pointer, which is always classified as a buffer that 'is not large enough to hold the data'.
So, other than the comment, the change looks good to me. I will push this one after the CI passes, with 'NULL buffer' replaced by 'zero-length buffer'.
-- Best regards, LIU Hao
OpenPGP_signature.asc
Description: OpenPGP digital signature
_______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
