fix bound checking on cursor move

changing most of the vt struct fields to unsigned, to avoid undefined
behaviour and use gotoxy for moving the cursor to correctly bound check
the cursor position

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

diff --git a/vncterm.c b/vncterm.c
index 3ca00ba17bb6c3c5999ab45ffa1769db2c1f8f07..70fccef76db8bd1dc2b149d5c48b64a9ac490571 100644 (file)
--- a/vncterm.c
+++ b/vncterm.c
@@ -1405,10 +1405,7 @@ vncterm_putchar (vncTerm *vt, unicode ch)
       if (vt->esc_buf[0] == 0) {
        vt->esc_buf[0] = 1;
       }
-      vt->cy -= vt->esc_buf[0];
-      if (vt->cy < 0) {
-       vt->cy = 0;
-      }
+      vncterm_gotoxy (vt, vt->cx, vt->cy - vt->esc_buf[0]);
       break;
     case 'B':
     case 'e':
@@ -1416,10 +1413,7 @@ vncterm_putchar (vncTerm *vt, unicode ch)
       if (vt->esc_buf[0] == 0) {
        vt->esc_buf[0] = 1;
       }
-      vt->cy += vt->esc_buf[0];
-      if (vt->cy >= vt->height) {
-       vt->cy = vt->height - 1;
-      }
+      vncterm_gotoxy (vt, vt->cx, vt->cy + vt->esc_buf[0]);
       break;
     case 'C':
     case 'a':
@@ -1427,20 +1421,14 @@ vncterm_putchar (vncTerm *vt, unicode ch)
       if (vt->esc_buf[0] == 0) {
        vt->esc_buf[0] = 1;
       }
-      vt->cx += vt->esc_buf[0];
-      if (vt->cx >= vt->width) {
-       vt->cx = vt->width - 1;
-      }
+      vncterm_gotoxy (vt, vt->cx + vt->esc_buf[0], vt->cy);
       break;
     case 'D':
       /* move cursor left */
       if (vt->esc_buf[0] == 0) {
        vt->esc_buf[0] = 1;
       }
-      vt->cx -= vt->esc_buf[0];
-      if (vt->cx < 0) {
-       vt->cx = 0;
-      }
+      vncterm_gotoxy (vt, vt->cx - vt->esc_buf[0], vt->cy);
       break;
     case 'G':
     case '`':

diff --git a/vncterm.h b/vncterm.h
index ffb5f2129c6676a638ee4215e62c6f21f8b0823c..8f7d8375f5489abccb9491e3424004ab6ce9b8b2 100644 (file)
--- a/vncterm.h
+++ b/vncterm.h
@@ -48,19 +48,19 @@ typedef struct vncTerm {
   // cursor
   TextAttributes cur_attrib;
   TextAttributes cur_attrib_saved;
-  int tty_state; // 0 - normal, 1 - ESC, 2 - CSI
+  unsigned int tty_state; // 0 - normal, 1 - ESC, 2 - CSI
   int cx; // cursor x position
   int cy; // cursor y position
   int cx_saved; // saved cursor x position
   int cy_saved; // saved cursor y position
-  int esc_buf[MAX_ESC_PARAMS];
-  int esc_count;
-  int esc_ques;
-  int esc_has_par;
+  unsigned int esc_buf[MAX_ESC_PARAMS];
+  unsigned int esc_count;
+  unsigned int esc_ques;
+  unsigned int esc_has_par;
   char osc_textbuf[4096];
   char osc_cmd;
-  int region_top;
-  int region_bottom;
+  unsigned int region_top;
+  unsigned int region_bottom;
 
   unsigned int charset:1; // G0 or G1
   unsigned int charset_saved:1; // G0 or G1