Revert "remove compatibility shims for firefox <= 80"

This reverts commit ae0fbd5.

extension/lib/commands.coffee

@@ -27,7 +27,10 @@ commands = {}
 
 
 commands.focus_location_bar = ({vim}) ->
-  vim.window.gURLBar.select()
+  try
+    vim.window.gURLBar.select() # fx76+
+  catch
+    vim.window.focusAndSelectUrlBar()
 
 commands.focus_search_bar = ({vim, count}) ->
   # The `.webSearch()` method opens a search engine in a tab if the search bar
@@ -754,7 +757,8 @@ commands.click_browser_element = ({vim}) ->
     })
     MarkerContainer.remove(window) # Better safe than sorry.
     markerContainer.container.classList.add('ui')
-    mainWindow = window.document.body
+    mainWindow = window.document.body or
+      window.document.getElementById('main-window') # fallback <fx72
     mainWindow.insertBefore(
       markerContainer.container,
       mainWindow.firstChild

extension/lib/markable-elements.coffee

@@ -287,10 +287,14 @@ tryPoint = (elementData, elementRect, x, dx, y, dy, tryRight = 0) ->
   return false if newX > viewport.right or newX > elementRect.right
   return tryPoint(elementData, elementRect, newX, 0, y, 0, tryRight - 1)
 
-# Elements in shadows roots may be “anonymous”. These are never returned by
-# `document.elementFromPoint` but their host elements are.
+# In XUL documents there are “anonymous” elements. These are never returned by
+# `document.elementFromPoint` but their closest non-anonymous parents are.
+# The same is true for Web Components (where their hosts are returned), with
+# the further caveat that they might be nested.
+# Note: getBindingParent() has been removed from fx72.
 normalize = (element) ->
-  element = e while (e = element.containingShadowRoot?.host)?
+  element = e while (e = element.ownerDocument.getBindingParent?(element))?
+  element = e while (e = element.containingShadowRoot?.host)? # >=fx72
   element = element.parentNode while element.prefix?
   return element
 

extension/lib/utils.coffee

@@ -23,7 +23,7 @@ XULControlElement = Ci.nsIDOMXULControlElement
 XULMenuListElement = Ci.nsIDOMXULMenuListElement
 
 # Traverse the DOM upwards until we hit its containing document (most likely an
-# HTMLDocument) or the ShadowRoot.
+# HTMLDocument or (<=fx68) XULDocument) or the ShadowRoot.
 getDocument = (e) -> if e.parentNode? then arguments.callee(e.parentNode) else e
 
 isInShadowRoot = (element) ->
@@ -97,7 +97,8 @@ isDevtoolsWindow = (window) ->
   # SecurityError; the `try` around it makes it `undefined` in such a case.
   return (try window.location?.href) in [
     'about:devtools-toolbox'
-    'chrome://devtools/content/framework/toolbox.xhtml'
+    'chrome://devtools/content/framework/toolbox.xul'
+    'chrome://devtools/content/framework/toolbox.xhtml' # fx72+
   ]
 
 # Note: this is possibly a bit overzealous, but Works For Now™.
@@ -321,7 +322,8 @@ contentAreaClick = (data, browser) ->
     originStoragePrincipal: data.originStoragePrincipal,
     triggeringPrincipal: data.triggeringPrincipal,
     csp: if data.csp then E10SUtils.deserializeCSP(data.csp) else null,
-    frameID: data.frameID,
+    frameOuterWindowID: data.frameOuterWindowID, # <=fx79
+    frameID: data.frameID, # >=fx80
     allowInheritPrincipal: true,
     openerBrowser: browser, # >=fx98
     hasValidUserGestureActivation: true, # >=fx103
@@ -396,9 +398,9 @@ simulateMouseEvents = (element, sequence, browserOffset) ->
       element.dispatchEvent(mouseEvent)
     else
       try
-        window.windowUtils.dispatchDOMEventViaPresShellForTesting(
-          element, mouseEvent
-        )
+        (window.windowUtils.dispatchDOMEventViaPresShellForTesting or
+         window.windowUtils.dispatchDOMEventViaPresShell # < fx73
+        )(element, mouseEvent)
       catch error
         if error.result != Cr.NS_ERROR_UNEXPECTED
           throw error