From 6ea793020f453af93161be185800b4419e7a06cb Mon Sep 17 00:00:00 2001
From: cyanpencil <lucadb96@gmail.com>
Date: Tue, 12 Jun 2018 16:36:14 +0200
Subject: [PATCH] Fix overflow in canvas.c + fix utf8 crop

---
 libr/cons/canvas.c | 37 ++++++++++++++++---------------------
 libr/core/panels.c |  4 ++--
 libr/util/str.c    |  4 ++++
 3 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/libr/cons/canvas.c b/libr/cons/canvas.c
index e650ca6386d26..f07067831feed 100644
--- a/libr/cons/canvas.c
+++ b/libr/cons/canvas.c
@@ -57,7 +57,6 @@ static int _get_piece(const char *p, char *chr) {
 	return p - q;
 }
 
-//XXX todo
 static const char **attr_at(RConsCanvas *c, int loc) {
 	int i, j, delta;
 	if (!c->color || c->attrslen == 0) {
@@ -94,7 +93,6 @@ static const char **attr_at(RConsCanvas *c, int loc) {
 	return NULL;
 }
 
-//XXX todo
 static void sort_attrs(RConsCanvas *c) {
 	int i, j;
 	RConsCanvasAttr value;
@@ -107,7 +105,6 @@ static void sort_attrs(RConsCanvas *c) {
 	}
 }
 
-//XXX todo
 static void stamp_attr(RConsCanvas *c, int loc, int length) {
 	int i;
 	const char **s;
@@ -131,7 +128,6 @@ static void stamp_attr(RConsCanvas *c, int loc, int length) {
 	}
 }
 
-//XXX todo
 /* check for ANSI sequences and use them as attr */
 static const char *set_attr(RConsCanvas *c, const char *s) {
 	if (!c || !s) {
@@ -168,26 +164,26 @@ R_API bool r_cons_canvas_gotoxy(RConsCanvas *c, int x, int y) {
 	y += c->sy;
 	x += c->sx;
 
-	if (x > c->blen[y] * 2) {
-		return false;
-	}
 	if (y > c->h * 2) {
 		return false;
 	}
-	if (x >= c->blen[y]) {
-		c->x = c->blen[y];
+	if (y >= c->h) {
+		y = c->h - 1;
 		ret = false;
 	}
-	if (y >= c->h) {
-		c->y = c->h;
+	if (y < 0) {
+		y = 0;
 		ret = false;
 	}
 	if (x < 0) {
 		//c->x = 0;
 		ret = false;
 	}
-	if (y < 0) {
-		c->y = 0;
+	if (x > c->blen[y] * 2) {
+		return false;
+	}
+	if (x >= c->blen[y]) {
+		c->x = c->blen[y];
 		ret = false;
 	}
 	if (x < c->blen[y] && x >= 0) {
@@ -269,19 +265,19 @@ static int utf8len_fixed(const char *s, int n) {
 	return j;
 }
 
-static int bytes_utf8len(const char *s, int n) {
+static int bytes_utf8len(const char *s, int n, int left) {
 	int i = 0;
-	while (s[i] && n > 0) {
+	while (s[i] && n > -1 && i < left) {
 		if ((s[i] & 0xc0) != 0x80) {
 			n--;
 		}
 		i++;
 	}
-	return i;
+	return i - 1;
 }
 
 static int expand_line (RConsCanvas *c, int real_len, int utf8_len) {
-	int buf_utf8_len = bytes_utf8len (c->b[c->y] + c->x, utf8_len);
+	int buf_utf8_len = bytes_utf8len (c->b[c->y] + c->x, utf8_len, c->blen[c->y] - c->x);
 	int goback = R_MAX (0, (buf_utf8_len - real_len));
 	int padding = (real_len - utf8_len) - goback;
 
@@ -320,8 +316,7 @@ R_API void r_cons_canvas_write(RConsCanvas *c, const char *s) {
 	int left, slen, attr_len, piece_len;
 	int orig_x = c->x, attr_x = c->x;
 
-	int x_padding = c->x - utf8len_fixed (c->b[c->y], c->x);
-	c->x += x_padding;
+	c->x = bytes_utf8len (c->b[c->y], c->x, c->blen[c->y]);
 
 	/* split the string into pieces of non-ANSI chars and print them normally,
 	** using the ANSI chars to set the attr of the canvas */
@@ -336,6 +331,7 @@ R_API void r_cons_canvas_write(RConsCanvas *c, const char *s) {
 		left =  c->blen[c->y] - c->x;
 		slen = R_MIN (left, piece_len);
 		attr_len = slen <= 0 && s_part != s? 1: slen;
+
 		if (attr_len > 0 && attr_x < c->blen[c->y]) {
 			stamp_attr (c, c->y*c->w + attr_x, attr_len);
 		}
@@ -358,8 +354,7 @@ R_API void r_cons_canvas_write(RConsCanvas *c, const char *s) {
 			if (*s == '\0' || c->y  >= c->h) {
 				break;
 			}
-			x_padding = utf8len_fixed (c->b[c->y], orig_x);
-			c->x = 2*orig_x - x_padding;
+			c->x = bytes_utf8len (c->b[c->y], orig_x, c->blen[c->y]);
 			attr_x = orig_x;
 		} else {
 			c->x += slen;
diff --git a/libr/core/panels.c b/libr/core/panels.c
index 8cfbf8fa493ef..0124c49fb123b 100644
--- a/libr/core/panels.c
+++ b/libr/core/panels.c
@@ -193,7 +193,7 @@ static void panelPrint(RCore *core, RConsCanvas *can, RPanel *panel, int color)
 			}
 			white[idx] = 0;
 			text = r_str_ansi_crop (cmdStr,
-					0, delta_y, panel->w + delta_x - 2, panel->h - 2 + delta_y);
+					0, delta_y, panel->w + delta_x - 3, panel->h - 2 + delta_y);
 			char *newText = r_str_prefix_all (text, white);
 			if (newText) {
 				free (text);
@@ -201,7 +201,7 @@ static void panelPrint(RCore *core, RConsCanvas *can, RPanel *panel, int color)
 			}
 		} else {
 			text = r_str_ansi_crop (cmdStr,
-					delta_x, delta_y, panel->w + delta_x - 2, panel->h - 2 + delta_y);
+					delta_x, delta_y, panel->w + delta_x - 3, panel->h - 2 + delta_y);
 		}
 		if (text) {
 			r_cons_canvas_write (can, text);
diff --git a/libr/util/str.c b/libr/util/str.c
index 7d2ef894697d9..1c5ae94f42711 100644
--- a/libr/util/str.c
+++ b/libr/util/str.c
@@ -1552,6 +1552,10 @@ R_API char *r_str_ansi_crop(const char *str, ut32 x, ut32 y, ut32 x2, ut32 y2) {
 			cw = 0;
 		} else {
 			if (ch >= y && ch < y2) {
+				if ((*str & 0xc0) == 0x80) {
+					*r++ = *str++;
+					continue;
+				}
 				if (*str == 0x1b && *(str + 1) == '[') {
 					const char *ptr = str;
 					if ((r_end - r) > 2) {