Revert "Remove scroll lock while focus is on captcha."

This reverts commit 46fd6744da2d4e8e3a2e3916ad6fd4483edc5ddf.

src/Posting/Captcha.v2.coffee

@@ -241,6 +241,9 @@ Captcha.v2 =
         if $ 'iframe[src^="https://www.google.com/recaptcha/api2/frame"]', node
           new MutationObserver(@fixBubble.bind(@, node)).observe node,
             attributes: true
+          # Prevent Recaptcha from keeping focus when popup dismissed.
+          if overlay = $ 'div[style*="position: fixed;"]', node
+            $.on overlay, 'click', -> $('#qr iframe')?.blur()
 
   fixBubble: (node) ->
     {bottom, right, width} = node.getBoundingClientRect()

src/Posting/QR.coffee

@@ -153,12 +153,28 @@ QR =
       unless QR.inBubble()
         QR.hasFocus = d.activeElement and QR.nodes.el.contains(d.activeElement)
         QR.nodes.el.classList.toggle 'focus', QR.hasFocus
+      # XXX Stop unwanted scrolling due to captcha.
+      if QR.captcha.isEnabled and QR.captcha is Captcha.v2 and !QR.captcha.noscript
+        if QR.inCaptcha()
+          QR.scrollY = window.scrollY
+          $.on d, 'scroll', QR.scrollLock
+        else
+          $.off d, 'scroll', QR.scrollLock
 
   inBubble: ->
     bubbles = $$ 'iframe[src^="https://www.google.com/recaptcha/api2/frame"]'
     d.activeElement in bubbles or bubbles.some (el) ->
       getComputedStyle(el).visibility isnt 'hidden' and el.getBoundingClientRect().bottom > 0
 
+  inCaptcha: ->
+    (d.activeElement?.nodeName is 'IFRAME' and QR.nodes.el.contains(d.activeElement)) or (QR.hasFocus and QR.inBubble())
+
+  scrollLock: ->
+    if QR.inCaptcha()
+      window.scroll window.scrollX, QR.scrollY
+    else
+      $.off d, 'scroll', QR.scrollLock
+
   hide: ->
     d.activeElement.blur()
     $.addClass QR.nodes.el, 'autohide'

src/css/style.css

@@ -1331,19 +1331,9 @@ input.field.tripped:not(:hover):not(:focus) {
 #qr .captcha-root {
   position: relative;
 }
-#qr .captcha-container > div {
+#qr .captcha-container > div > div {
   margin: auto;
 }
-/* scrollable with scroll bar hidden; prevents scroll on space press */
-:root.blink #qr .captcha-container > div {
-  width: 304px;
-  overflow: hidden;
-}
-:root.blink #qr .captcha-container > div > div:first-of-type {
-  overflow-y: scroll;
-  overflow-x: hidden;
-  padding-right: 15px;
-}
 #qr .captcha-counter {
   display: block;
   width: 100%;