Keep source files below navigation bar

TESTING.md

@@ -172,9 +172,10 @@ xcrun simctl launch booted de.rfc1437.gotcha
       Swift, and a scripting or markup language. Keywords, strings, comments,
       types, and punctuation use plausible language-specific highlighting.
 - [ ] Open a source file containing a line wider than the screen. It does not
-      word-wrap; horizontal dragging pans smoothly across the complete line
-      without blank, black, clipped, delayed, or jumping text. Vertical
-      scrolling, selection, and copying still work.
+      word-wrap, its first line starts below the navigation bar, and horizontal
+      dragging pans smoothly across the complete line without blank, black,
+      clipped, delayed, or jumping text. Vertical scrolling, selection, and
+      copying still work.
 - [ ] Open Markdown files using the supported extensions (`.md`, `.markdown`,
       `.mdown`, and `.mkd`). **Preview** is selected by default and renders
       headings, paragraphs, emphasis, links, lists, task lists, blockquotes,

ios/Sources/DetailScreens.swift

@@ -458,11 +458,12 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
         paragraph.lineBreakMode = .byClipping
         text.addAttribute(.paragraphStyle, value: paragraph, range: NSRange(location: 0, length: text.length))
 
-        let scrollView = UIScrollView(frame: view.bounds)
-        scrollView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        let scrollView = UIScrollView()
+        scrollView.translatesAutoresizingMaskIntoConstraints = false
         scrollView.alwaysBounceHorizontal = true
         scrollView.isDirectionalLockEnabled = true
         scrollView.showsHorizontalScrollIndicator = true
+        scrollView.contentInsetAdjustmentBehavior = .never
 
         let textView = UITextView(frame: .zero)
         textView.textContainer.size = CGSize(
@@ -480,6 +481,12 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
         scrollView.addSubview(textView)
         displayedView = scrollView
         view.addSubview(scrollView)
+        NSLayoutConstraint.activate([
+            scrollView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
+            scrollView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
+            scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
+            scrollView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
+        ])
         updateSourceLayout()
     }