From: Dominik Csapak <d.csapak@proxmox.com>
Date: Fri, 5 May 2017 12:19:06 +0000 (+0200)
Subject: fix bound checking on cursor move
X-Git-Url: https://git.proxmox.com/?p=vncterm.git;a=commitdiff_plain;h=8392857fa71a2bb3cf140cf24f9fece507770662

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 3ca00ba..70fccef 100644
--- 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 ffb5f21..8f7d837 100644
--- 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