From: Philip Oakley <philipoakley@xxxxxxx> This constant is not defined in MSVC's headers. In UCRT's fcntl.h, _O_RDONLY, _O_WRONLY and _O_RDWR are defined as 0, 1 and 2, respectively. Yes, that means that UCRT breaks with the tradition that O_RDWR == O_RDONLY | O_WRONLY. It is a perfectly legal way to define those constants, though, therefore we need to take care of defining O_ACCMODE accordingly. This is particularly important in order to keep our "open() can set errno to EISDIR" emulation working: it tests that (flags & O_ACCMODE) is not identical to O_RDONLY before going on to test specifically whether the file for which open() reported EACCES is, in fact, a directory. Signed-off-by: Philip Oakley <philipoakley@xxxxxxx> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> --- compat/msvc.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/compat/msvc.h b/compat/msvc.h index 04b4750b87..d336d80670 100644 --- a/compat/msvc.h +++ b/compat/msvc.h @@ -19,6 +19,8 @@ #undef ERROR typedef int sigset_t; +/* open for reading, writing, or both (not in fcntl.h) */ +#define O_ACCMODE (_O_RDONLY | _O_WRONLY | _O_RDWR) #include "compat/mingw.h" -- gitgitgadget
