Merge baa5973128 into 07fd3e685a

Component
---------
- Bugfix: Fix a crash with ResizeableSplit. See #1023.
  - Clamp screen size to terminal size.
  - Disallow `ResizeableSplit` with negative size.

Dom
---
- Bugfix: Disallow specifying a negative size constraint. See #1023.

Bug: https://github.com/ArthurSonzogni/FTXUI/issues/1023

CHANGELOG.md

@@ -1,6 +1,17 @@
 Changelog
 =========
 
+Development
+-----------
+### Component
+- Bugfix: Fix a crash with ResizeableSplit. See #1023.
+  - Clamp screen size to terminal size.
+  - Disallow `ResizeableSplit` with negative size.
+
+### Dom
+- Bugfix: Disallow specifying a negative size constraint. See #1023.
+
+
 6.0.2 (2025-03-30)
 -----
 

src/ftxui/component/resizable_split.cpp

@@ -77,16 +77,16 @@ class ResizableSplitBase : public ComponentBase {
 
     switch (options_->direction()) {
       case Direction::Left:
-        options_->main_size() = event.mouse().x - box_.x_min;
+        options_->main_size() = std::max(0, event.mouse().x - box_.x_min);
         return true;
       case Direction::Right:
-        options_->main_size() = box_.x_max - event.mouse().x;
+        options_->main_size() = std::max(0, box_.x_max - event.mouse().x);
         return true;
       case Direction::Up:
-        options_->main_size() = event.mouse().y - box_.y_min;
+        options_->main_size() = std::max(0, event.mouse().y - box_.y_min);
         return true;
       case Direction::Down:
-        options_->main_size() = box_.y_max - event.mouse().y;
+        options_->main_size() = std::max(0, box_.y_max - event.mouse().y);
         return true;
     }
 

src/ftxui/component/screen_interactive.cpp

@@ -34,6 +34,7 @@
 #include "ftxui/dom/requirement.hpp"                  // for Requirement
 #include "ftxui/screen/pixel.hpp"                     // for Pixel
 #include "ftxui/screen/terminal.hpp"                  // for Dimensions, Size
+#include "ftxui/screen/util.hpp"                      // for util::clamp
 
 #if defined(_WIN32)
 #define DEFINE_CONSOLEV2_PROPERTIES
@@ -917,15 +918,15 @@ void ScreenInteractive::Draw(Component component) {
       break;
     case Dimension::TerminalOutput:
       dimx = terminal.dimx;
-      dimy = document->requirement().min_y;
+      dimy = util::clamp(document->requirement().min_y, 0, terminal.dimy);
       break;
     case Dimension::Fullscreen:
       dimx = terminal.dimx;
       dimy = terminal.dimy;
       break;
     case Dimension::FitComponent:
-      dimx = std::min(document->requirement().min_x, terminal.dimx);
-      dimy = std::min(document->requirement().min_y, terminal.dimy);
+      dimx = util::clamp(document->requirement().min_x, 0, terminal.dimx);
+      dimy = util::clamp(document->requirement().min_y, 0, terminal.dimy);
       break;
   }
 

src/ftxui/dom/size.cpp

@@ -19,7 +19,7 @@ class Size : public Node {
       : Node(unpack(std::move(child))),
         direction_(direction),
         constraint_(constraint),
-        value_(value) {}
+        value_(std::max(0, value)) {}
 
   void ComputeRequirement() override {
     Node::ComputeRequirement();

src/ftxui/screen/terminal.cpp

@@ -48,25 +48,38 @@ Dimensions& FallbackSize() {
   return g_fallback_size;
 }
 
-const char* Safe(const char* c) {
-  return (c != nullptr) ? c : "";
-}
-
 bool Contains(const std::string& s, const char* key) {
   return s.find(key) != std::string::npos;
 }
 
+// https://github.com/gabime/spdlog/blob/885b5473e291833b148eeac3b7ce227e582cd88b/include/spdlog/details/os-inl.h#L566
+std::string getenv_safe(const char *field) {
+#if defined(_MSC_VER)
+#if defined(__cplusplus_winrt)
+  return std::string{};  // not supported under uwp
+#else
+  size_t len = 0;
+  char buf[1024];
+  bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
+  return ok ? buf : std::string{};
+#endif
+#else  // revert to getenv
+  char *buf = ::getenv(field); // NOLINT(*-mt-unsafe)
+  return buf ? buf : std::string{};
+#endif
+}
+
 Terminal::Color ComputeColorSupport() {
 #if defined(__EMSCRIPTEN__)
   return Terminal::Color::TrueColor;
 #endif
 
-  std::string COLORTERM = Safe(std::getenv("COLORTERM"));  // NOLINT
+  std::string COLORTERM = getenv_safe("COLORTERM");
   if (Contains(COLORTERM, "24bit") || Contains(COLORTERM, "truecolor")) {
     return Terminal::Color::TrueColor;
   }
 
-  std::string TERM = Safe(std::getenv("TERM"));  // NOLINT
+  std::string TERM = getenv_safe("TERM");
   if (Contains(COLORTERM, "256") || Contains(TERM, "256")) {
     return Terminal::Color::Palette256;
   }