lineedit: correctly handle prompt longer than screen width. closes bug 3414

1 files changed, 18 insertions, 14 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index c91efd40c..fb595c010 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -80,10 +80,9 @@ struct lineedit_statics {
         volatile unsigned cmdedit_termw; /* = 80; */ /* actual terminal width */
         sighandler_t previous_SIGWINCH_handler;
 
-
-        int cmdedit_x;           /* real x terminal position */
-        int cmdedit_y;           /* pseudoreal y terminal position */
-        int cmdedit_prmt_len;    /* length of prompt (without colors etc) */
+        unsigned cmdedit_x;        /* real x terminal position */
+        unsigned cmdedit_y;        /* pseudoreal y terminal position */
+        unsigned cmdedit_prmt_len; /* length of prompt (without colors etc) */
 
         unsigned cursor;
         unsigned command_len;
@@ -199,7 +198,7 @@ static void cmdedit_set_out_char(int next_char)
         {
                 bb_putchar(c);
         }
-        if (++cmdedit_x >= (int)cmdedit_termw) {
+        if (++cmdedit_x >= cmdedit_termw) {
                 /* terminal is scrolled down */
                 cmdedit_y++;
                 cmdedit_x = 0;
@@ -262,12 +261,12 @@ static void input_backward(unsigned num)
                 return;
         cursor -= num;
 
-        if ((unsigned)cmdedit_x >= num) {
+        if (cmdedit_x >= num) {
                 cmdedit_x -= num;
                 if (num <= 4) {
                         /* This is longer by 5 bytes on x86.
-                         * Also gets mysteriously
-                         * miscompiled for some ARM users.
+                         * Also gets miscompiled for ARM users
+                         * (busybox.net/bugs/view.php?id=2274).
                          * printf(("\b\b\b\b" + 4) - num);
                          * return;
                          */
@@ -282,9 +281,12 @@ static void input_backward(unsigned num)
 
         /* Need to go one or more lines up */
         num -= cmdedit_x;
-        count_y = 1 + (num / cmdedit_termw);
-        cmdedit_y -= count_y;
-        cmdedit_x = cmdedit_termw * count_y - num;
+        {
+                unsigned w = cmdedit_termw; /* volatile var */
+                count_y = 1 + (num / w);
+                cmdedit_y -= count_y;
+                cmdedit_x = w * count_y - num;
+        }
         /* go to 1st column; go up; go to correct column */
         printf("\r" "\033[%dA" "\033[%dC", count_y, cmdedit_x);
 }
@@ -292,10 +294,12 @@ static void input_backward(unsigned num)
 static void put_prompt(void)
 {
         out1str(cmdedit_prompt);
-        cmdedit_x = cmdedit_prmt_len;
         cursor = 0;
-// Huh? what if cmdedit_prmt_len >= width?
-        cmdedit_y = 0;                  /* new quasireal y */
+        {
+                unsigned w = cmdedit_termw; /* volatile var */
+                cmdedit_y = cmdedit_prmt_len / w; /* new quasireal y */
+                cmdedit_x = cmdedit_prmt_len % w;
+        }
 }
 
 /* draw prompt, editor line, and clear tail */