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)