From b8d88fd8a208868df0769ddedd49d85079f8c57b Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 19 Mar 2024 11:50:31 -0700
Subject: [PATCH] terminal: deleteLines with zero count should do nothing

---
 src/terminal/Terminal.zig | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 40c475edc..77e76acc6 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -1353,6 +1353,9 @@ pub fn insertLines(self: *Terminal, count: usize) void {
 ///
 /// Moves the cursor to the left margin.
 pub fn deleteLines(self: *Terminal, count_req: usize) void {
+    // Rare, but happens
+    if (count_req == 0) return;
+
     // If the cursor is outside the scroll region we do nothing.
     if (self.screen.cursor.y < self.scrolling_region.top or
         self.screen.cursor.y > self.scrolling_region.bottom or
@@ -5719,6 +5722,16 @@ test "Terminal: deleteLines left/right scroll region high count" {
     }
 }
 
+test "Terminal: deleteLines zero" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, .{ .cols = 2, .rows = 5 });
+    defer t.deinit(alloc);
+
+    // This should do nothing
+    t.setCursorPos(1, 1);
+    t.deleteLines(0);
+}
+
 test "Terminal: default style is empty" {
     const alloc = testing.allocator;
     var t = try init(alloc, .{ .rows = 5, .cols = 5 });