Abort all fibers along a call chain when one aborts.

test/core/fiber/try.wren

@@ -8,34 +8,3 @@ System.print(fiber.try())
 // expect: before
 // expect: Bool does not implement 'unknownMethod'.
 System.print("after try") // expect: after try
-
-var fiber2 = Fiber.new {
-  var fiberInner = Fiber.new {
-    System.print("before")
-    true.unknownMethod
-    System.print("after")
-  }
-  fiberInner.call()
-}
-
-System.print(fiber2.try())
-// expect: before
-// expect: Bool does not implement 'unknownMethod'.
-System.print("after try") // expect: after try
-
-var fiber3 = Fiber.new {
-  var fiberInner = Fiber.new {
-    var fiberInnerInner = Fiber.new {
-      System.print("before")
-      true.unknownMethod
-      System.print("after")
-    }
-    fiberInnerInner.call()
-  }
-  fiberInner.call()
-}
-
-System.print(fiber3.try())
-// expect: before
-// expect: Bool does not implement 'unknownMethod'.
-System.print("after try") // expect: after try

test/core/fiber/try_through_call.wren

@@ -0,0 +1,49 @@
+// A runtime error percolates through the fiber call chain until it hits a
+// try(). Every intermediate fiber is aborted too.
+
+var fiber1 = Fiber.new {
+  System.print("1 before")
+  Fiber.abort("Abort!")
+  System.print("1 after")
+}
+
+var fiber2 = Fiber.new {
+  System.print("2 before")
+  fiber1.call()
+  System.print("2 after")
+}
+
+var fiber3 = Fiber.new {
+  System.print("3 before")
+  fiber2.call()
+  System.print("3 after")
+}
+
+var fiber4 = Fiber.new {
+  System.print("4 before")
+  fiber3.try()
+  System.print("4 after")
+}
+
+var fiber5 = Fiber.new {
+  System.print("5 before")
+  fiber4.call()
+  System.print("5 after")
+}
+
+fiber5.call()
+// expect: 5 before
+// expect: 4 before
+// expect: 3 before
+// expect: 2 before
+// expect: 1 before
+// expect: 4 after
+// expect: 5 after
+System.print("after") // expect: after
+
+// The fibers between the aborted one and the tried one are all errored.
+System.print(fiber1.error) // expect: Abort!
+System.print(fiber2.error) // expect: Abort!
+System.print(fiber3.error) // expect: Abort!
+System.print(fiber4.error) // expect: null
+System.print(fiber5.error) // expect: null