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

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

1 files changed, 14 insertions, 9 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 3905b8cc4..a62ab6d29 100644
--- 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)