Fix bug: cursor down could go past edbox_len.

1 files changed, 38 insertions, 5 deletions

diff --git a/src/edbox.c b/src/edbox.c
index bcc41a4..d5728c2 100644
--- a/src/edbox.c
+++ b/src/edbox.c
@@ -9,6 +9,9 @@
 
 /* TODO: tab completion */
 
+char *old_edbox[EDBOX_SIZE];
+static u16 old_len;
+
 int edbox_visible = 0;
 static u16 edbox_pos; /* range 0 to EDBOX_SIZE - 1 */
 u16 edbox_len; /* idem */
@@ -72,6 +75,20 @@ void edbox_putc(char c) {
 	}
 }
 
+static void copy_to_old(void) {
+	if(!edbox_len) return;
+	memcpy(old_edbox, edit_box, edbox_len);
+	memset(old_edbox + edbox_len, 0, (EDBOX_SIZE - 1) - edbox_len);
+	old_len = edbox_len;
+}
+
+static void restore_old(void) {
+	edbox_clear();
+	hide_cursor();
+	memcpy(edit_box, old_edbox, old_len);
+	edbox_pos = edbox_len = old_len;
+}
+
 static void fake_keystroke(char c) {
 	keyclick();
 	OS.ch = 0xff;
@@ -95,6 +112,24 @@ static void backspace(void) {
 	del_char();
 }
 
+static void up(void) {
+	if(!edbox_len) {
+		restore_old();
+	} else {
+		if(edbox_pos > 39)
+			edbox_pos -= 40;
+		else
+			edbox_pos = 0;
+	}
+}
+
+static void down(void) {
+	if(edbox_pos > 199) return;
+	edbox_pos += 40;
+	if(edbox_pos > edbox_len)
+		edbox_pos = edbox_len;
+}
+
 static void word_left(char del) {
 	if(!edbox_pos) return;
 	if(!del) edbox_pos--;
@@ -140,6 +175,7 @@ static void normal_keystroke(void) {
 	switch(c) {
 		case CH_EOL:
 			// hide_cursor(); // already done by the caller
+			copy_to_old();
 			edbox_hide();
 			if(edbox_callback)
 				(*edbox_callback)();
@@ -176,13 +212,10 @@ static void normal_keystroke(void) {
 			if(edbox_pos < edbox_len) edbox_pos++;
 			break;
 		case CH_CURS_UP:
-			if(edbox_pos > 39) edbox_pos -= 40;
+			up();
 			break;
 		case CH_CURS_DOWN:
-			if(edbox_pos < edbox_len - 40)
-				edbox_pos += 40;
-			else
-				edbox_pos = edbox_len;
+			down();
 			break;
 		case CH_DELCHR:
 			del_char();