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.

4 files changed, 34 insertions, 32 deletions

diff --git a/editors/vi.c b/editors/vi.c
index 13f0ae8ee..74028e2b4 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -456,9 +456,7 @@ struct globals {
 #if ENABLE_FEATURE_VI_USE_SIGNALS
         sigjmp_buf restart;     // int_handler() jumps to location remembered here
 #endif
-#if !ENABLE_PLATFORM_MINGW32
         struct termios term_orig; // remember what the cooked mode was
-#endif
         int cindex;               // saved character index for up/down motion
         smallint keep_index;      // retain saved character index
 #if ENABLE_FEATURE_VI_COLON
@@ -700,7 +698,6 @@ static int mysleep(int hund)
 }
 
 //----- Set terminal attributes --------------------------------
-#if !ENABLE_PLATFORM_MINGW32
 static void rawmode(void)
 {
         // no TERMIOS_CLEAR_ISIG: leave ISIG on - allow signals
@@ -712,10 +709,6 @@ static void cookmode(void)
         fflush_all();
         tcsetattr_stdin_TCSANOW(&term_orig);
 }
-#else
-#define rawmode() ((void)0)
-#define cookmode fflush_all
-#endif
 
 //----- Terminal Drawing ---------------------------------------
 // The terminal is made up of 'rows' line of 'columns' columns.
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index c4f0c65f1..9bf2f89a5 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -726,7 +726,12 @@ static void input_forward(void)
 #if !ENABLE_PLATFORM_MINGW32
                 put_cur_glyph_and_inc_cursor();
 #else
-                inc_cursor();
+        {
+                if (terminal_mode(FALSE) & VT_INPUT)
+                        put_cur_glyph_and_inc_cursor();
+                else
+                        inc_cursor();
+        }
 #endif
 }
 
@@ -2579,7 +2584,7 @@ static void sigaction2(int sig, struct sigaction *act)
  */
 int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *command, int maxsize)
 {
-        int len IF_NOT_PLATFORM_MINGW32(, n);
+        int len, n;
         int timeout;
 #if ENABLE_FEATURE_TAB_COMPLETION
         smallint lastWasTab = 0;
@@ -2589,9 +2594,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
         smallint vi_cmdmode = 0;
 #endif
         struct termios initial_settings;
-#if !ENABLE_PLATFORM_MINGW32
         struct termios new_settings;
-#endif
         char read_key_buffer[KEYCODE_BUFFER_SIZE];
 
         INIT_S();
@@ -2600,15 +2603,13 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
         cmdedit_termw = 80;
         IF_FEATURE_EDITING_VI(delptr = delbuf;)
 
-#if !ENABLE_PLATFORM_MINGW32
         n = get_termios_and_make_raw(STDIN_FILENO, &new_settings, &initial_settings, 0
                 | TERMIOS_CLEAR_ISIG /* turn off INTR (ctrl-C), QUIT, SUSP */
         );
+#if !ENABLE_PLATFORM_MINGW32
         if (n != 0 || (initial_settings.c_lflag & (ECHO|ICANON)) == ICANON) {
 #else
-        initial_settings.c_cc[VINTR] = CTRL('C');
-        initial_settings.c_cc[VEOF] = CTRL('D');
-        if (!isatty(0) || !isatty(1)) {
+        if (n != 0 || !isatty(0) || !isatty(1)) {
 #endif
                 /* Happens when e.g. stty -echo was run before.
                  * But if ICANON is not set, we don't come here.
@@ -2661,9 +2662,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
 #endif
 #define command command_must_not_be_used
 
-#if !ENABLE_PLATFORM_MINGW32
         tcsetattr_stdin_TCSANOW(&new_settings);
-#endif
 
 #if 0
         for (i = 0; i <= state->max_history; i++)
@@ -3150,10 +3149,8 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
         free_tab_completion_data();
 #endif
 
-#if !ENABLE_PLATFORM_MINGW32
         /* restore initial_settings */
         tcsetattr_stdin_TCSANOW(&initial_settings);
-#endif
 #if ENABLE_FEATURE_EDITING_WINCH
         /* restore SIGWINCH handler */
         sigaction_set(SIGWINCH, &S.SIGWINCH_handler);
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 */
diff --git a/util-linux/more.c b/util-linux/more.c
index 07275131e..84ce37bc7 100644
--- a/util-linux/more.c
+++ b/util-linux/more.c
@@ -62,6 +62,7 @@ static void tcsetattr_tty_TCSANOW(struct termios *settings)
         tcsetattr(G.tty_fileno, TCSANOW, settings);
 }
 
+#if !ENABLE_PLATFORM_MINGW32
 static void gotsig(int sig UNUSED_PARAM)
 {
         /* bb_putchar_stderr doesn't use stdio buffering,
@@ -70,6 +71,7 @@ static void gotsig(int sig UNUSED_PARAM)
         tcsetattr_tty_TCSANOW(&G.initial_settings);
         _exit(EXIT_FAILURE);
 }
+#endif
 
 #define CONVERTED_TAB_SIZE 8
 
@@ -159,12 +161,13 @@ int more_main(int argc UNUSED_PARAM, char **argv)
                                  * to get input from the user.
                                  */
                                 for (;;) {
-#if !ENABLE_PLATFORM_MINGW32
                                         fflush_all();
-                                        input = getc(tty);
-#else
-                                        input = _getch();
+#if ENABLE_PLATFORM_MINGW32
+                                        if (!(terminal_mode(FALSE) & VT_INPUT))
+                                                input = _getch();
+                                        else
 #endif
+                                        input = getc(tty);
                                         input = tolower(input);
                                         /* Erase the last message */
                                         printf("\r%*s\r", len, "");