Am 18.12.2016 um 16:37 schrieb Johannes Sixt:
winansi.c is all about overriding MSVCRT's console handling. If we are
connected to a console, then by the time isatty() is called (from
outside the emulation layer), all handling of file descriptors 1 and 2
is already outside MSVCRT's control. In particular, we have determined
unambiguously whether a terminal is connected (see is_console()). I
suggest to have the implementation below (on top of the patch I'm
responding to).
What do you think?
I thought a bit more about this approach, and I retract it. I think it
does not work when Git is connected to an MSYS TTY, i.e., when the
"console" is in reality the pipe that is detected in detect_msys_tty().
At the same time I wonder how your original winansi_isatty() could have
worked: In this case, MSVCRT's isatty() would return 1 (because
detect_msys_tty() has set things up that this happens), but then
winansi_isatty() checks whether the handle underlying fd 0, 1 or 2 is a
real Windows console. But it is not: it is a pipe. Am I missing something?
diff --git a/compat/winansi.c b/compat/winansi.c
index ba360be69b..1748d17777 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -575,9 +575,8 @@ static void detect_msys_tty(int fd)
int winansi_isatty(int fd)
{
- int res = isatty(fd);
-
- if (res) {
+ switch (fd) {
+ case 0:
/*
* Make sure that /dev/null is not fooling Git into believing
* that we are connected to a terminal, as "_isatty() returns a
@@ -586,21 +585,19 @@ int winansi_isatty(int fd)
*
* https://msdn.microsoft.com/en-us/library/f4s0ddew.aspx
*/
- HANDLE handle = winansi_get_osfhandle(fd);
- if (fd == STDIN_FILENO) {
+ {
+ HANDLE handle = (HANDLE)_get_osfhandle(fd);
DWORD dummy;
- if (!GetConsoleMode(handle, &dummy))
- res = 0;
- } else if (fd == STDOUT_FILENO || fd == STDERR_FILENO) {
- CONSOLE_SCREEN_BUFFER_INFO dummy;
-
- if (!GetConsoleScreenBufferInfo(handle, &dummy))
- res = 0;
+ return !!GetConsoleMode(handle, &dummy);
}
+ case 1:
+ return !!hconsole1;
+ case 2:
+ return !!hconsole2;
}
- return res;
+ return isatty(fd);
}
void winansi_init(void)