From 2663a4d1b3170cb2a4dca5e6f1f3535f44b30e44 Mon Sep 17 00:00:00 2001 From: Gabriel Schneider Date: Mon, 28 Sep 2026 16:47:26 -0300 Subject: No panic from a notice wider than its band, or from the rest of its class The showcase GUI died in joinNotice on a long shader-error notice: with the tagline narrower than the body, the band hides more columns (skip) than a long message has padding (pad), and `skip..@min(pad, ..)` ran backwards. An audit of draw.zig, Layer.zig, Presentation.zig and animation.zig found the same class elsewhere, all fixed: - a multi-row pane tag or header scrolled for its caret's line sliced a shorter row past its end (paintPaneTag, renderHeaderLayer); - a zero-width column tag kept an earlier frame's viewport, and a column move's clip took it below zero (now saturating, and the early return resets the viewport and caret); - a tag line past 65535 columns overflowed tag_scroll's u16; - a hover left over from a bigger window dashed past the grid; - a border drag over a column that went away, a move preview past a shrunken grid, a column-move rail at zero columns; - Layer.pointAt cast a host's unchecked float metrics (web) to u16; - Text.insertVerticalCursor read past its lines for a cursor whose text changed under it. Regressions: a test of a notice wider than its band through Msg and through setMessage (the Post.zig compile-error path), which panics without the fix; and a monkey over the core at a gui's metrics (random resizes to a cell, long notices, prompts, multi-row tags, clicks, keys), 400 steps in the suite, PARDES_FUZZ_SEED/STEPS for longer runs; 60 seeds x 3000 steps clean. Shared files touched: none of the list (draw.zig, Layer.zig, Text.zig). --- src/Text.zig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/Text.zig') diff --git a/src/Text.zig b/src/Text.zig index 43dd8a95..f6780935 100644 --- a/src/Text.zig +++ b/src/Text.zig @@ -118,7 +118,8 @@ pub fn fromModalCursor(t: *Text, c: modal.Cursor) void { pub fn insertVerticalCursor(lines: []const []const u8, c: modal.Cursor, down: bool) modal.Cursor { if (lines.len == 0) return c; - const row = if (down) @min(c.row + 1, lines.len - 1) else c.row -| 1; + // A cursor past the lines (its text changed under it) moves from the last. + const row = if (down) @min(c.row + 1, lines.len - 1) else @min(c.row, lines.len) -| 1; const target = lines[row]; if (target.len == 0) return .{ .row = row, .col = 0 }; const source = if (c.row < lines.len) lines[c.row] else ""; -- cgit v1.3