From c2474dc2aa716f03522edec5c07292489ef48894 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Thu, 2 Mar 2017 15:52:28 +0100 Subject: [PATCH] mingw: fix isatty() after dup2() We newly handle isatty() by special-casing the stdin/stdout/stderr file descriptors, caching the return value. However, we missed the case where dup2() overrides the respective file descriptor. That poses a problem e.g. where the `show` builtin asks for a pager very early, the `setup_pager()` function sets the pager depending on the return value of `isatty()` and then redirects stdout. Subsequently, `cmd_log_init_finish()` calls `setup_pager()` *again*. What should happen now is that `isatty()` reports that stdout is *not* a TTY and consequently stdout should be left alone. Let's override dup2() to handle this appropriately. This fixes https://github.com/git-for-windows/git/issues/1077 Signed-off-by: Johannes Schindelin --- compat/mingw.h | 3 +++ compat/winansi.c | 12 ++++++++++++ 2 files changed, 15 insertions(+) diff --git a/compat/mingw.h b/compat/mingw.h index a93ce87d21b9cd..0af67843d7680e 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -475,6 +475,9 @@ int mingw_raise(int sig); int winansi_isatty(int fd); #define isatty winansi_isatty +int winansi_dup2(int oldfd, int newfd); +#define dup2 winansi_dup2 + void winansi_init(void); HANDLE winansi_get_osfhandle(int fd); diff --git a/compat/winansi.c b/compat/winansi.c index 986bfb30cf5b06..7e3534e9a16e88 100644 --- a/compat/winansi.c +++ b/compat/winansi.c @@ -457,6 +457,18 @@ static void die_lasterr(const char *fmt, ...) va_end(params); } +#undef dup2 +int winansi_dup2(int oldfd, int newfd) +{ + int ret = dup2(oldfd, newfd); + + if (!ret && newfd >= 0 && newfd <= 2) + fd_is_interactive[newfd] = oldfd < 0 || oldfd > 2 ? + 0 : fd_is_interactive[oldfd]; + + return ret; +} + static HANDLE duplicate_handle(HANDLE hnd) { HANDLE hresult, hproc = GetCurrentProcess();