Dactyloidae iOS initial commit

mobile/ios/Client/UIScrollViewSwizzled.swift

@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import Shared
+
+// Workaround for bug 1417152, whereby NaN bounds are being set on the scrollview when viewing PDFs in the web view.
+// Is fixed in WebKit, remove this file when the fix arrives in iOS release.
+
+private let swizzling: (UIScrollView.Type) -> Void = { obj in
+    let originalSelector = #selector(setter: UIView.bounds)
+    let swizzledSelector = #selector(obj.swizzle_setBounds(bounds:))
+    let originalMethod = class_getInstanceMethod(obj, originalSelector)
+    let swizzledMethod = class_getInstanceMethod(obj, swizzledSelector)
+    method_exchangeImplementations(originalMethod, swizzledMethod)
+}
+
+extension UIScrollView {
+    open override class func initialize() {
+        // make sure this isn't a subclass
+        guard self == UIScrollView.self else {
+            return
+        }
+        swizzling(self)
+    }
+
+    func swizzle_setBounds(bounds: CGRect) {
+        [bounds.origin.x, bounds.origin.y, bounds.size.width, bounds.size.height].forEach() { val in
+            if val.isNaN || val.isInfinite {
+                Sentry.shared.send(message: "Bad scrollview bounds detected [infinite/nan].")
+                return
+            }
+        }
+
+        [bounds.size.width, bounds.size.height].forEach() { val in
+            if val < 0 {
+                Sentry.shared.send(message: "Bad scrollview bounds detected [negative size].")
+                return
+            }
+        }
+
+        self.swizzle_setBounds(bounds: bounds)
+    }
+}