Win32: avoid any automatic LF to CRLF conversions when writing to stdout

* At least the MSVCRT does this by default, i.e. the translation mode of stdout
  is not _O_BINARY.
* This broke piping through SciTECO with --stdin --stdout, as this relies on SciTECO's
  builtin EOL normalization. Instead, you would get DOS linebreaks on output even if the
  source stream contains only UNIX linebreaks.
* It would also break binary filters.
* It seems to be safe to print only LF also for regular stdio (help and error messages),
  so I simply disaply the stdout (and stdin and stderr) EOL translation globally.
* Also fixes Troff warnings due to the .in preprocessor writing output with DOS linebreaks.
* Added a test case. All future platforms shouldn't perform any unexpected EOL translations
  on output.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
index 3ad4333..a4ee7bd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -30,6 +30,11 @@
 #include <glib/gprintf.h>
 #include <glib/gstdio.h>
 
+#ifdef G_OS_WIN32
+#include <fcntl.h>
+#include <io.h>
+#endif
+
 #ifdef HAVE_SYS_CAPSICUM_H
 #include <sys/capsicum.h>
 #endif
@@ -362,6 +367,20 @@ main(int argc, char **argv)
 	g_autoptr(GError) error = NULL;
 	teco_int_t ret = EXIT_SUCCESS;
 
+#ifdef G_OS_WIN32
+	/*
+	 * Windows might by default perform EOL translations, especially
+	 * when writing to stdout, i.e. translate LF to CRLF.
+	 * This would break at the very least --stdout, where you are
+	 * expected to get the linebreaks configured on the current buffer via EL.
+	 * It would also break binary filters on Windows.
+	 * Since printing LF to the console is safe nowadays, we just do that
+	 * globally.
+	 */
+	for (gint fd = 0; fd <= 2; fd++)
+		_setmode(fd, _O_BINARY);
+#endif
+
 #ifdef DEBUG_PAUSE
 	/* Windows debugging hack (see above) */
 	system("pause");