Commit 80b32af

noname <noname@inventati.org>
2014-04-22 18:08:13
Simplify tdeletechar and tinsertblank and fix memory corruption.
Current CSI parsing code uses strtol to parse arguments and allows them to be negative. Negative argument is not properly handled in tdeletechar and tinsertblank and results in memory corruption in memmove. Reproduce with printf '\e[-500@' Patch also removes special handling for corner case and simplifies the code. Removed term.dirty[term.c.y] = 1 because tclearregion sets dirty flag.
master
1 parent 16ac85b
Changed files (1)
st.c
st.c
@@ -1586,37 +1586,31 @@ tclearregion(int x1, int y1, int x2, int y2) {
 
 void
 tdeletechar(int n) {
-	int src = term.c.x + n;
-	int dst = term.c.x;
-	int size = term.col - src;
+	int dst, src, size;
 
-	term.dirty[term.c.y] = 1;
+	LIMIT(n, 0, term.col - term.c.x);
 
-	if(src >= term.col) {
-		tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
-		return;
-	}
+	dst = term.c.x;
+	src = term.c.x + n;
+	size = term.col - src;
 
 	memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
-			size * sizeof(Glyph));
+	        size * sizeof(Glyph));
 	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
 }
 
 void
 tinsertblank(int n) {
-	int src = term.c.x;
-	int dst = src + n;
-	int size = term.col - dst;
+	int dst, src, size;
 
-	term.dirty[term.c.y] = 1;
+	LIMIT(n, 0, term.col - term.c.x);
 
-	if(dst >= term.col) {
-		tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
-		return;
-	}
+	dst = term.c.x + n;
+	src = term.c.x;
+	size = term.col - dst;
 
 	memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
-			size * sizeof(Glyph));
+	        size * sizeof(Glyph));
 	tclearregion(src, term.c.y, dst - 1, term.c.y);
 }