lineedit: limit ASK_TERMINAL to the case when we can't find out the width

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 3905b8cc49dd5f0cb6f245390289035553557907..a62ab6d295c7b61ce97a75394518e58dbf9d82fd 100644 (file)
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -149,6 +149,7 @@ struct lineedit_statics {
        CHAR_T delbuf[DELBUFSIZ];  /* a place to store deleted characters */
 #endif
 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
+       smallint unknown_width;
        smallint sent_ESC_br6n;
 #endif
 
@@ -1610,14 +1611,16 @@ static void ask_terminal(void)
         * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
         * read(0, "\n", 1)      = 1  <-- oh crap, user's input got in first
         */
-       struct pollfd pfd;
-
-       pfd.fd = STDIN_FILENO;
-       pfd.events = POLLIN;
-       if (safe_poll(&pfd, 1, 0) == 0) {
-               S.sent_ESC_br6n = 1;
-               fputs("\033" "[6n", stdout);
-               fflush_all(); /* make terminal see it ASAP! */
+       if (S.unknown_width) { /* only if window size is not known */
+               struct pollfd pfd;
+
+               pfd.fd = STDIN_FILENO;
+               pfd.events = POLLIN;
+               if (safe_poll(&pfd, 1, 0) == 0) {
+                       S.sent_ESC_br6n = 1;
+                       fputs("\033" "[6n", stdout);
+                       fflush_all(); /* make terminal see it ASAP! */
+               }
        }
 }
 #else
@@ -1763,11 +1766,13 @@ static void cmdedit_setwidth(unsigned w, int redraw_flg)
 
 static void win_changed(int nsig)
 {
+       int sv_errno = errno;
        unsigned width;
-       get_terminal_width_height(0, &width, NULL);
+       IF_FEATURE_EDITING_ASK_TERMINAL(S.unknown_width =) get_terminal_width_height(0, &width, NULL);
        cmdedit_setwidth(width, nsig /* - just a yes/no flag */);
        if (nsig == SIGWINCH)
                signal(SIGWINCH, win_changed); /* rearm ourself */
+       errno = sv_errno;
 }
 
 static int lineedit_read_key(char *read_key_buffer)