From d75108e96058b6e00da6306a7d99c9555f645434 Mon Sep 17 00:00:00 2001
From: Arthur Sonzogni <sonzogniarthur@gmail.com>
Date: Mon, 10 Feb 2025 22:51:31 +0100
Subject: [PATCH] Fix linear_gradient float precision bug.
This was reported by:
https://github.com/ArthurSonzogni/FTXUI/issues/998
Indeed, the `t` interpolation factor, which is itself interpolated might become
slightly larger than 1.0. This is due to the float precision.
This was supposedly handled, but there was an off-by-one error in the check.
Along the way, fix a bug found by a fuzzer.
Bug: https://github.com/ArthurSonzogni/FTXUI/issues/998
Fixed: https://github.com/ArthurSonzogni/FTXUI/issues/998
---
CHANGELOG.md | 3 +++
cmake/ftxui_set_options.cmake | 4 ----
cmake/ftxui_test.cmake | 1 +
src/ftxui/component/dropdown.cpp | 6 ++++-
src/ftxui/component/dropdown_test.cpp | 34 +++++++++++++++++++++++++++
src/ftxui/dom/linear_gradient.cpp | 6 ++++-
6 files changed, 48 insertions(+), 6 deletions(-)
create mode 100644 src/ftxui/component/dropdown_test.cpp
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fbe57ae2..1b607ece 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -44,6 +44,9 @@ current (development)
See #932
- Feature: Add `SliderOption::on_change`. This allows to set a callback when the
slider value changes. See #938.
+- Bugfix: Handle `Dropdown` with no entries.
+- Bugfix: Fix crash in `LinearGradient` due to float precision and an off-by-one
+ mistake. See #998.
### Dom
- Feature: Add `hscroll_indicator`. It display an horizontal indicator
diff --git a/cmake/ftxui_set_options.cmake b/cmake/ftxui_set_options.cmake
index 6e5a8e00..185739e4 100644
--- a/cmake/ftxui_set_options.cmake
+++ b/cmake/ftxui_set_options.cmake
@@ -83,10 +83,6 @@ function(ftxui_set_options library)
target_compile_options(${library} PRIVATE "-Wpedantic")
target_compile_options(${library} PRIVATE "-Wshadow")
target_compile_options(${library} PRIVATE "-Wunused")
-
- if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
- target_compile_options(${library} PRIVATE "-Wuseless-cast")
- endif()
endif()
endif()
diff --git a/cmake/ftxui_test.cmake b/cmake/ftxui_test.cmake
index 56b21bd9..7ff1b2d7 100644
--- a/cmake/ftxui_test.cmake
+++ b/cmake/ftxui_test.cmake
@@ -13,6 +13,7 @@ add_executable(ftxui-tests
src/ftxui/component/component_test.cpp
src/ftxui/component/component_test.cpp
src/ftxui/component/container_test.cpp
+ src/ftxui/component/dropdown_test.cpp
src/ftxui/component/hoverable_test.cpp
src/ftxui/component/input_test.cpp
src/ftxui/component/menu_test.cpp
diff --git a/src/ftxui/component/dropdown.cpp b/src/ftxui/component/dropdown.cpp
index b268dd9f..690a6e2d 100644
--- a/src/ftxui/component/dropdown.cpp
+++ b/src/ftxui/component/dropdown.cpp
@@ -47,7 +47,11 @@ Component Dropdown(DropdownOption option) {
Element Render() override {
radiobox.selected =
util::clamp(radiobox.selected(), 0, int(radiobox.entries.size()) - 1);
- title_ = radiobox.entries[selected_()];
+ selected_ = util::clamp(selected_(), 0, int(radiobox.entries.size()) - 1);
+
+ if (selected_() >= 0) {
+ title_ = radiobox.entries[selected_()];
+ }
return transform(*open_, checkbox_->Render(), radiobox_->Render());
}
diff --git a/src/ftxui/component/dropdown_test.cpp b/src/ftxui/component/dropdown_test.cpp
new file mode 100644
index 00000000..44434d12
--- /dev/null
+++ b/src/ftxui/component/dropdown_test.cpp
@@ -0,0 +1,34 @@
+// Copyright 2025 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
+
+#include "ftxui/component/component.hpp" // for Horizontal, Vertical, Button, Tab
+#include "ftxui/component/component_base.hpp" // for ComponentBase, Component
+#include "ftxui/component/event.hpp" // for Event, Event::Tab, Event::TabReverse, Event::ArrowDown, Event::ArrowLeft, Event::ArrowRight, Event::ArrowUp
+#include "gtest/gtest.h" // for AssertionResult, Message, TestPartResult, EXPECT_EQ, EXPECT_FALSE, Test, EXPECT_TRUE, TEST
+
+namespace ftxui {
+
+TEST(DropdownTest, Empty) {
+ std::vector<std::string> list = {};
+ int index = 0;
+ auto dropdown = Dropdown(list, &index);
+
+ dropdown->OnEvent(Event::Return);
+
+ auto screen = Screen(8, 8);
+ auto document = dropdown->Render();
+ Render(screen, document);
+
+ EXPECT_EQ(screen.ToString(),
+ "â•â”€â”€â”€â”€â”€â”€â•®\r\n"
+ "│↓ │\r\n"
+ "├──────┤\r\n"
+ "│ │\r\n"
+ "│ │\r\n"
+ "│ │\r\n"
+ "│ │\r\n"
+ "╰──────╯");
+}
+
+} // namespace ftxui
diff --git a/src/ftxui/dom/linear_gradient.cpp b/src/ftxui/dom/linear_gradient.cpp
index 0f7d1761..5dda646d 100644
--- a/src/ftxui/dom/linear_gradient.cpp
+++ b/src/ftxui/dom/linear_gradient.cpp
@@ -97,7 +97,11 @@ Color Interpolate(const LinearGradientNormalized& gradient, float t) {
// Find the right color in the gradient's stops.
size_t i = 1;
while (true) {
- if (i > gradient.positions.size()) {
+ // Note that `t` might be slightly greater than 1.0 due to floating point
+ // precision. This is why we need to handle the case where `t` is greater
+ // than the last stop's position.
+ // See https://github.com/ArthurSonzogni/FTXUI/issues/998
+ if (i >= gradient.positions.size()) {
const float half = 0.5F;
return Color::Interpolate(half, gradient.colors.back(),
gradient.colors.back());
--
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