Fix up the rest of the Sixel stuff... only three minor issues remain:

1) Instead of parsing as it's read, it gets all the data in a string, then
   parses the string... this is wasteful. This is the toughest one to fix.
2) The background clear thing in the raster attribute command doesn't
   work if the image scrolls. Somthing Must Be Done.
3) No save/restore pixel data, so menus and scrollback break images.
   This one is fairly straightforward to fix.

src/conio/cterm.c

@@ -1276,10 +1276,12 @@ void draw_sixel(struct cterminal *cterm, char *str)
 	unsigned x,y;
 	int vmode;
 	struct text_info ti;
-	int i;
+	int i, j, k;
 	char *p;
 	int max_row;
 	int	olddmc;
+	int pixels_sent = 0;
+	int first_pass = 1;
 
 	olddmc=*cterm->hold_update;
 	*cterm->hold_update=0;
@@ -1303,6 +1305,33 @@ void draw_sixel(struct cterminal *cterm, char *str)
 		p++;
 		hgrid = strtoul(p, &p, 10);
 	}
+	switch (ratio) {
+		case 0:
+		case 1:
+			iv = 2;
+			ih = 1;
+			break;
+		case 2:
+			iv = 5;
+			ih = 1;
+			break;
+		case 3:
+		case 4:
+			iv = 3;
+			ih = 1;
+			break;
+		case 5:
+		case 6:
+			iv = 2;
+			ih = 1;
+			break;
+		case 7:
+		case 8:
+		case 9:
+			iv = 1;
+			ih = 1;
+			break;
+	}
 	p++;
 	// TODO: It seems the official documentation is wrong?  Nobody gets this right.
 	trans=1;
@@ -1312,17 +1341,24 @@ void draw_sixel(struct cterminal *cterm, char *str)
 		if (*p >= '?' && *p <= '~') {
 			unsigned data = *p - '?';
 
+			pixels_sent = 1;
 			for (i=0; i<6; i++) {
 				if (data & (1<<i)) {
-					setpixel(x, y+i, fg);
+					for (j = 0; j < iv; j++) {
+						for (k = 0; k < ih; k++)
+							setpixel(x+k, y+(i*iv)+j, fg);
+					}
 				}
 				else {
-					if (!trans) {
-						setpixel(x, y+i, bg);
+					if (first_pass && !trans) {
+						for (j = 0; j < iv; j++) {
+							for (k = 0; k < ih; k++)
+								setpixel(x+k, y+(i*iv)+j, bg);
+						}
 					}
 				}
 			}
-			x++;
+			x+=ih;
 			// TODO: Check X
 			if (repeat)
 				repeat--;
@@ -1332,19 +1368,26 @@ void draw_sixel(struct cterminal *cterm, char *str)
 		else {
 			switch(*p) {
 				case '"':	// Raster Attributes
-					p++;
-					iv = strtoul(p, &p, 10);
-					if (*p == ';') {
-						p++;
-						ih = strtoul(p, &p, 10);
-					}
-					if (*p == ';') {
-						p++;
-						height = strtoul(p, &p, 10);
-					}
-					if (*p == ';') {
+					if (!pixels_sent) {
 						p++;
-						width = strtoul(p, &p, 10);
+						iv = strtoul(p, &p, 10);
+						if (*p == ';') {
+							p++;
+							ih = strtoul(p, &p, 10);
+						}
+						if (*p == ';') {
+							p++;
+							width = strtoul(p, &p, 10);
+						}
+						if (*p == ';') {
+							p++;
+							height = strtoul(p, &p, 10);
+						}
+						// TODO: If the image scrolls, the background isn't set
+						for (i = 0; i<height*iv; i++) {
+							for (j = 0; j < width*ih; j++)
+								setpixel(x+j, y+i, bg);
+						}
 					}
 					break;
 				case '!':	// Repeat
@@ -1384,6 +1427,7 @@ void draw_sixel(struct cterminal *cterm, char *str)
 				case '$':	// Graphics Carriage Return
 					x = left;
 					p++;
+					first_pass = 0;
 					break;
 				case '-':	// Graphics New Line
 					max_row = cterm->height;
@@ -1391,12 +1435,13 @@ void draw_sixel(struct cterminal *cterm, char *str)
 						max_row = cterm->bottom_margin - cterm->top_margin + 1;
 
 					x = left;
-					y += 6;
-					if (y + 5 >= (cterm->y + max_row - 1) * vparams[vmode].charheight) {
+					y += 6*iv;
+					while ((y + 6*iv - 1) >= (cterm->y + max_row - 1) * vparams[vmode].charheight) {
 						scrollup(cterm);
 						y -= vparams[vmode].charheight;
 					}
 					p++;
+					first_pass = 1;
 					break;
 				default:
 					p++;
@@ -1408,7 +1453,7 @@ void draw_sixel(struct cterminal *cterm, char *str)
 	x = x / vparams[vmode].charwidth + 1;
 	x -= (cterm->x - 1);
 
-	y = (y+6) / vparams[vmode].charheight + 1;
+	y = (y+6*iv-1) / vparams[vmode].charheight + 1;
 	y -= (cterm->y - 1);
 
 	*cterm->hold_update=olddmc;