Index: node_modules/d3-geo/src/clip/line.js
===================================================================
--- node_modules/d3-geo/src/clip/line.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-geo/src/clip/line.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,59 @@
+export default function(a, b, x0, y0, x1, y1) {
+  var ax = a[0],
+      ay = a[1],
+      bx = b[0],
+      by = b[1],
+      t0 = 0,
+      t1 = 1,
+      dx = bx - ax,
+      dy = by - ay,
+      r;
+
+  r = x0 - ax;
+  if (!dx && r > 0) return;
+  r /= dx;
+  if (dx < 0) {
+    if (r < t0) return;
+    if (r < t1) t1 = r;
+  } else if (dx > 0) {
+    if (r > t1) return;
+    if (r > t0) t0 = r;
+  }
+
+  r = x1 - ax;
+  if (!dx && r < 0) return;
+  r /= dx;
+  if (dx < 0) {
+    if (r > t1) return;
+    if (r > t0) t0 = r;
+  } else if (dx > 0) {
+    if (r < t0) return;
+    if (r < t1) t1 = r;
+  }
+
+  r = y0 - ay;
+  if (!dy && r > 0) return;
+  r /= dy;
+  if (dy < 0) {
+    if (r < t0) return;
+    if (r < t1) t1 = r;
+  } else if (dy > 0) {
+    if (r > t1) return;
+    if (r > t0) t0 = r;
+  }
+
+  r = y1 - ay;
+  if (!dy && r < 0) return;
+  r /= dy;
+  if (dy < 0) {
+    if (r > t1) return;
+    if (r > t0) t0 = r;
+  } else if (dy > 0) {
+    if (r < t0) return;
+    if (r < t1) t1 = r;
+  }
+
+  if (t0 > 0) a[0] = ax + t0 * dx, a[1] = ay + t0 * dy;
+  if (t1 < 1) b[0] = ax + t1 * dx, b[1] = ay + t1 * dy;
+  return true;
+}