dwindle: avoid sending negative sizes to wlr

fixes #4591

3 files changed, 12 insertions, 4 deletions

diff --git a/src/helpers/Box.cpp b/src/helpers/Box.cpp
index 3d57bc79..d3f5d36c 100644
--- a/src/helpers/Box.cpp
+++ b/src/helpers/Box.cpp
@@ -105,6 +105,13 @@ CBox& CBox::expand(const double& value) {
     return *this;
 }
 
+CBox& CBox::noNegativeSize() {
+    std::clamp(w, 0.0, std::numeric_limits<double>::infinity());
+    std::clamp(h, 0.0, std::numeric_limits<double>::infinity());
+
+    return *this;
+}
+
 CBox CBox::roundInternal() {
     float newW = x + w - std::floor(x);
     float newH = y + h - std::floor(y);
diff --git a/src/helpers/Box.hpp b/src/helpers/Box.hpp
index a1ed83be..fd31a7b7 100644
--- a/src/helpers/Box.hpp
+++ b/src/helpers/Box.hpp
@@ -51,6 +51,7 @@ class CBox {
     CBox&                    transform(const wl_output_transform t, double w, double h);
     CBox&                    addExtents(const SWindowDecorationExtents& e);
     CBox&                    expand(const double& value);
+    CBox&                    noNegativeSize();
 
     CBox                     copy() const;
 
diff --git a/src/layout/DwindleLayout.cpp b/src/layout/DwindleLayout.cpp
index 85111fcd..4058121f 100644
--- a/src/layout/DwindleLayout.cpp
+++ b/src/layout/DwindleLayout.cpp
@@ -22,13 +22,13 @@ void SDwindleNodeData::recalcSizePosRecursive(bool force, bool horizontalOverrid
         if (SPLITSIDE) {
             // split left/right
             const float FIRSTSIZE = box.w / 2.0 * splitRatio;
-            children[0]->box      = CBox{box.x, box.y, FIRSTSIZE, box.h};
-            children[1]->box      = CBox{box.x + FIRSTSIZE, box.y, box.w - FIRSTSIZE, box.h};
+            children[0]->box      = CBox{box.x, box.y, FIRSTSIZE, box.h}.noNegativeSize();
+            children[1]->box      = CBox{box.x + FIRSTSIZE, box.y, box.w - FIRSTSIZE, box.h}.noNegativeSize();
         } else {
             // split top/bottom
             const float FIRSTSIZE = box.h / 2.0 * splitRatio;
-            children[0]->box      = CBox{box.x, box.y, box.w, FIRSTSIZE};
-            children[1]->box      = CBox{box.x, box.y + FIRSTSIZE, box.w, box.h - FIRSTSIZE};
+            children[0]->box      = CBox{box.x, box.y, box.w, FIRSTSIZE}.noNegativeSize();
+            children[1]->box      = CBox{box.x, box.y + FIRSTSIZE, box.w, box.h - FIRSTSIZE}.noNegativeSize();
         }
 
         children[0]->recalcSizePosRecursive(force);