1 files changed, 54 insertions, 1 deletions
diff --git a/src/draw.zig b/src/draw.zig
index a2005e59..b8cf4e7d 100644
--- a/src/draw.zig
+++ b/src/draw.zig
@@ -197,8 +197,11 @@ fn focusedCursorBox(p: *const Pardes, s: *const Surface) ?animation.Box {
         const caret = layer.cursor orelse continue;
         if (layer.rows == 0 or layer.viewport.y + caret.y != cursor.y) continue;
         if (cursor.x < layer.viewport.x or cursor.x >= layer.viewport.x + layer.viewport.w) continue;
-        const x = @as(f32, @floatFromInt(layer.viewport.x)) + @as(f32, @floatFromInt(caret.x)) * tw / bw;
         const w = if (caret.bar) tw / bw / 8 else tw / bw;
+        // A caret past a full row's end sits at the tag's right edge, where
+        // the grid's is clamped too.
+        const right = @as(f32, @floatFromInt(layer.viewport.x + layer.viewport.w));
+        const x = @min(@as(f32, @floatFromInt(layer.viewport.x)) + @as(f32, @floatFromInt(caret.x)) * tw / bw, right - w);
         return .{ .x = x, .y = @as(f32, @floatFromInt(cursor.y)) + (bh - th) / 2 / bh, .w = w, .h = th / bh };
     }
     return .{ .x = @floatFromInt(cursor.x), .y = @floatFromInt(cursor.y), .w = if (cursor.bar) 1.0 / 8.0 else 1, .h = 1 };
@@ -1787,6 +1790,56 @@ test "the focused cursor glides a jump, lands a step at once, and is exact at re
     try std.testing.expectEqual(@as(u8, 2), s.chrome.cursor_glide);
 }
 
+test "a tag caret past its row's end glides to the tag's right edge, where the layer's is" {
+    if (!builtins.capabilities.lift) return error.SkipZigTest;
+    const p = try Pardes.init(std.testing.allocator, .{ .cols = 60, .rows = 16 });
+    defer p.deinit();
+    p.update(.{ .resize = .{ .cols = 60, .rows = 16, .row_metrics = .{ .body_w = 10, .body_h = 20, .tagline_w = 6, .tagline_h = 12 } } });
+    const pane = try p.setTestFile("text\n");
+    var arena: std.heap.ArenaAllocator = .init(std.testing.allocator);
+    defer arena.deinit();
+    // The tag's text grown a letter at a time, the caret after its last one
+    // in insert mode, until a row is full and the caret is past its end.
+    var found = false;
+    var n: usize = 1;
+    while (n < 200 and !found) : (n += 1) {
+        _ = arena.reset(.retain_capacity);
+        if (pane.tag.own) |own| p.gpa.free(own);
+        const own = try p.gpa.alloc(u8, n);
+        @memset(own, 'x');
+        own[0] = ' ';
+        pane.tag.own = own;
+        tagline.enterTag(p, pane);
+        const whole = try tagline.tagText(p, arena.allocator(), pane);
+        pane.tag.mode = .insert;
+        pane.tag.cur_row = 0;
+        pane.tag.cur_col = @intCast(modal.lineSlice(whole, 0).len);
+        p.sync();
+        const s = try p.render(arena.allocator());
+        const layer = for (s.tagLayers()) |*layer| {
+            if (layer.rows != 0 and layer.kind == .pane and layer.cursor != null) break layer;
+        } else continue;
+        const caret = layer.cursor.?;
+        const right: f32 = @floatFromInt(layer.viewport.x + layer.viewport.w);
+        const box = focusedCursorBox(p, s).?;
+        // Never past the tag's right edge, and the pane's.
+        try std.testing.expect(box.x + box.w <= right + 1e-4);
+        try std.testing.expect(box.x + box.w <= @as(f32, @floatFromInt(p.rects[p.active].x + p.rects[p.active].w)));
+        const at = @as(f32, @floatFromInt(layer.viewport.x)) + @as(f32, @floatFromInt(caret.x)) * 6 / 10;
+        if (at + box.w <= right) {
+            // Inside its row: exactly where the layer's caret is.
+            try std.testing.expectApproxEqAbs(at, box.x, 1e-4);
+        } else {
+            // Past it: on the tag's right edge, as the pixel shell's caret
+            // is (gui.zig cursorBoxes).
+            try std.testing.expectApproxEqAbs(right, box.x + box.w, 1e-4);
+            try std.testing.expectApproxEqAbs(@as(f32, 6.0 / 10.0 / 8.0), box.w, 1e-4);
+            found = true;
+        }
+    }
+    try std.testing.expect(found);
+}
+
 test "a terminal's cursor lands with scrolling output, never gliding against it" {
     if (!builtins.capabilities.lift or !pardes.terminal_panes) return error.SkipZigTest;
     const p = try Pardes.init(std.testing.allocator, .{ .cols = 80, .rows = 12 });