win32: add support for virtual terminal input

Alter certain applets to support virtual terminal input, if enabled.

In many places this is achieved by building previously excluded
upstream terminal-handling code.  The busybox-w32 implementation
of termios(3) functions does nothing if virtual terminal input is
disabled, so it can be invoked regardless.

Some applet-specific terminal-handling code is also required.

This affects less, more, vi and command line editing in the shell.
(The `more` applet isn't enabled in the default configuration.)

This series of patches adds about 1.7KB to the binaries.

1 files changed, 18 insertions, 9 deletions

diff --git a/miscutils/less.c b/miscutils/less.c
index 842031ca3..467c76e2a 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -240,9 +240,7 @@ struct globals {
         smallint winsize_err;
 #endif
         smallint terminated;
-#if !ENABLE_PLATFORM_MINGW32
         struct termios term_orig, term_less;
-#endif
         char kbd_input[KEYCODE_BUFFER_SIZE];
 };
 #define G (*ptr_to_globals)
@@ -304,9 +302,7 @@ struct globals {
 static void set_tty_cooked(void)
 {
         fflush_all();
-#if !ENABLE_PLATFORM_MINGW32
         tcsetattr(kbd_fd, TCSANOW, &term_orig);
-#endif
 }
 
 /* Move the cursor to a position (x,y), where (0,0) is the
@@ -1132,8 +1128,11 @@ static void reinitialize(void)
         buffer_fill_and_print();
 }
 
-#if !ENABLE_PLATFORM_MINGW32
+#if ENABLE_PLATFORM_MINGW32
+static int64_t unix_getch_nowait(void)
+#else
 static int64_t getch_nowait(void)
+#endif
 {
         int rd;
         int64_t key64;
@@ -1194,11 +1193,15 @@ static int64_t getch_nowait(void)
         set_tty_cooked();
         return key64;
 }
-#else
+
+#if ENABLE_PLATFORM_MINGW32
 static int64_t getch_nowait(void)
 {
         int64_t c;
 
+        if (terminal_mode(FALSE) & VT_INPUT)
+                return unix_getch_nowait();
+
 retry:
         c = _getch();
         if (c == 0 || c == 0xe0) {
@@ -1894,6 +1897,8 @@ int less_main(int argc, char **argv)
 {
 #if !ENABLE_PLATFORM_MINGW32
         char *tty_name;
+#else
+        HANDLE h;
 #endif
         int tty_fd;
 
@@ -1980,12 +1985,16 @@ int less_main(int argc, char **argv)
         G.kbd_fd_orig_flags = ndelay_on(tty_fd);
         kbd_fd = tty_fd; /* save in a global */
 #else
-        kbd_fd = tty_fd = 0;
+        h = CreateFileA("CONIN$", GENERIC_READ | GENERIC_WRITE,
+                                        FILE_SHARE_READ, NULL, OPEN_EXISTING,
+                                        FILE_ATTRIBUTE_NORMAL, NULL);
+        if (h == INVALID_HANDLE_VALUE)
+                bb_simple_error_msg_and_die("unable to open console");
+
+        kbd_fd = tty_fd = _open_osfhandle((intptr_t)h, O_BINARY);
 #endif
 
-#if !ENABLE_PLATFORM_MINGW32
         get_termios_and_make_raw(tty_fd, &term_less, &term_orig, TERMIOS_RAW_CRNL_INPUT);
-#endif
 
         IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(tty_fd, &width, &max_displayed_line);
         /* 20: two tabstops + 4 */