diff --git a/dom/bindings/Codegen.py b/dom/bindings/Codegen.py
index 8ee732cca3..8985863e8f 100644
--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -1109,6 +1109,12 @@ class CGHeaders(CGWrapper):
         # Now find all the things we'll need as arguments because we
         # need to wrap or unwrap them.
         bindingHeaders = set()
+
+        # KeyframeAnimationOptions.webidl is doing something VERY screwy and
+        # Unified Building really sucks so directly include this
+        if prefix == "KeyframeAnimationOptionsBinding":
+          bindingHeaders.add("mozilla/dom/PrimitiveConversions.h")
+
         declareIncludes = set(declareIncludes)
 
         def addHeadersForType((t, dictionary)):
diff --git a/dom/bindings/WebIDLGlobalNameHash.cpp b/dom/bindings/WebIDLGlobalNameHash.cpp
index 7477b52e7a..981a1a3953 100644
--- a/dom/bindings/WebIDLGlobalNameHash.cpp
+++ b/dom/bindings/WebIDLGlobalNameHash.cpp
@@ -4,8 +4,12 @@
  * 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/. */
 
+#include "jswrapper.h"
 #include "WebIDLGlobalNameHash.h"
 #include "js/GCAPI.h"
+#include "XrayWrapper.h"
+#include "XPCWrapper.h"
+#include "mozilla/dom/Selection.h"
 #include "mozilla/HashFunctions.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/dom/DOMJSProxyHandler.h"
diff --git a/dom/bindings/WebIDLGlobalNameHash.h b/dom/bindings/WebIDLGlobalNameHash.h
index bbe0153950..cd7be2c699 100644
--- a/dom/bindings/WebIDLGlobalNameHash.h
+++ b/dom/bindings/WebIDLGlobalNameHash.h
@@ -8,6 +8,7 @@
 #define mozilla_dom_WebIDLGlobalNameHash_h__
 
 #include "js/RootingAPI.h"
+#include "nsString.h"
 #include "nsTArray.h"
 
 namespace mozilla {
diff --git a/dom/bindings/moz.build b/dom/bindings/moz.build
index ed8a4d37e5..ca82b48a8f 100644
--- a/dom/bindings/moz.build
+++ b/dom/bindings/moz.build
@@ -89,7 +89,7 @@ LOCAL_INCLUDES += [
     '/media/webrtc/signaling/src/peerconnection',
 ]
 
-UNIFIED_SOURCES += [
+SOURCES += [
     'BindingUtils.cpp',
     'CallbackInterface.cpp',
     'CallbackObject.cpp',
diff --git a/dom/bindings/nsScriptError.h b/dom/bindings/nsScriptError.h
index b8049d0a00..ac8099c1c3 100644
--- a/dom/bindings/nsScriptError.h
+++ b/dom/bindings/nsScriptError.h
@@ -14,8 +14,13 @@
 #include "jsapi.h"
 #include "js/RootingAPI.h"
 
+#include "jswrapper.h"
+#include "nsCOMArray.h"
+#include "nsContentUtils.h"
+#include "nsCycleCollectionParticipant.h"
 #include "nsIScriptError.h"
 #include "nsString.h"
+#include "nsStringFwd.h"
 
 class nsScriptErrorNote final : public nsIScriptErrorNote {
  public:
diff --git a/dom/bindings/nsScriptErrorWithStack.cpp b/dom/bindings/nsScriptErrorWithStack.cpp
index 74c00999fd..0a8df38b36 100644
--- a/dom/bindings/nsScriptErrorWithStack.cpp
+++ b/dom/bindings/nsScriptErrorWithStack.cpp
@@ -22,7 +22,7 @@ using namespace mozilla::dom;
 namespace {
 
 static nsCString
-FormatStackString(JSContext* cx, HandleObject aStack) {
+FormatStackString(JSContext* cx, JS::HandleObject aStack) {
     JS::RootedString formattedStack(cx);
 
     if (!JS::BuildStackString(cx, aStack, &formattedStack)) {
@@ -111,7 +111,7 @@ nsScriptErrorWithStack::ToString(nsACString& /*UTF8*/ aResult)
     }
 
     JSContext* cx = jsapi.cx();
-    RootedObject stack(cx, mStack);
+    JS::RootedObject stack(cx, mStack);
     nsCString stackString = FormatStackString(cx, stack);
     nsCString combined = message + NS_LITERAL_CSTRING("\n") + stackString;
     aResult.Assign(combined);
diff --git a/dom/security/nsCSPUtils.cpp b/dom/security/nsCSPUtils.cpp
index d07ad79457..6d4f297d6d 100644
--- a/dom/security/nsCSPUtils.cpp
+++ b/dom/security/nsCSPUtils.cpp
@@ -555,7 +555,21 @@ permitsPort(const nsAString& aEnforcementScheme,
 
   int32_t resourcePort;
   nsresult rv = aResourceURI->GetPort(&resourcePort);
-  NS_ENSURE_SUCCESS(rv, false);
+  if (NS_FAILED(rv) && aEnforcementPort.IsEmpty()) {
+    // If we cannot get a Port (e.g. because of an Custom Protocol handler)
+    // we need to check if a default port is associated with the Scheme
+    if (aEnforcementScheme.IsEmpty()) {
+      return false;
+    }
+    int defaultPortforScheme =
+        NS_GetDefaultPort(NS_ConvertUTF16toUTF8(aEnforcementScheme).get());
+
+    // If there is no default port associated with the Scheme (
+    // defaultPortforScheme == -1) or it is an externally handled protocol (
+    // defaultPortforScheme == 0 ) and the csp does not enforce a port - we can
+    // allow not having a port
+    return (defaultPortforScheme == -1 || defaultPortforScheme == 0);
+  }
 
   // Avoid unnecessary string creation/manipulation and don't block the
   // load if the resource to be loaded uses the default port for that
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index a8309314f8..556e35406a 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -1056,6 +1056,7 @@ protected:
   bool ParseOneFamily(nsAString& aFamily, bool& aOneKeyword, bool& aQuoted);
   bool ParseFamily(nsCSSValue& aValue);
   bool ParseFontFeatureSettings(nsCSSValue& aValue);
+  bool ParseFontVariationSettings(nsCSSValue& aValue);
   bool ParseFontSrc(nsCSSValue& aValue);
   bool ParseFontSrcFormat(InfallibleTArray<nsCSSValue>& values);
   bool ParseFontRanges(nsCSSValue& aValue);
@@ -12092,6 +12093,8 @@ CSSParserImpl::ParseSingleValuePropertyByFunction(nsCSSValue& aValue,
       return ParseFontVariantNumeric(aValue);
     case eCSSProperty_font_feature_settings:
       return ParseFontFeatureSettings(aValue);
+    case eCSSProperty_font_variation_settings:
+      return ParseFontVariationSettings(aValue);
     case eCSSProperty_font_weight:
       return ParseFontWeight(aValue);
     case eCSSProperty_image_orientation:
@@ -15315,6 +15318,19 @@ CSSParserImpl::ParseFontFeatureSettings(nsCSSValue& aValue)
   return true;
 }
 
+bool
+CSSParserImpl::ParseFontVariationSettings(nsCSSValue& aValue)
+{
+  // TODO: Actually implement this.
+  
+  // This stub is here because websites insist on considering this
+  // very hardware-dependent and O.S.-variable low-level font-control
+  // as a "critical feature" which it isn't as there is 0 guarantee
+  // that font variation settings are supported or honored by any
+  // operating system used by the client.
+  return true;
+}
+
 bool
 CSSParserImpl::ParseListStyle()
 {
diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index 07db6d3ddc..411f982a4e 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -2036,6 +2036,20 @@ CSS_PROP_FONT(
     kFontVariantPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
+CSS_PROP_FONT(
+    font-variation-settings,
+    font_variation_settings,
+    FontVariationSettings,
+    CSS_PROPERTY_PARSE_VALUE |
+        CSS_PROPERTY_VALUE_PARSER_FUNCTION |
+        CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
+        CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+    "layout.css.font-variations.stub",
+    0,
+    nullptr,
+    CSS_PROP_NO_OFFSET,
+    eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-weight,
     font_weight,
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 647f7f6dc5..910c1de8ae 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -674,9 +674,9 @@ nsComputedDOMStyle::UpdateCurrentStyleSources(bool aNeedsLayoutFlush)
     mPresShell->GetPresContext()->GetRestyleGeneration();
 
   if (mStyleContext) {
-    // We can't rely on the undisplayed restyle generation if mElement is
-    // out-of-document, since that generation is not incremented for DOM changes
-    // on out-of-document elements.
+    // We can't rely on the undisplayed restyle generation if mElement is
+    // out-of-document, since that generation is not incremented for DOM changes
+    // on out-of-document elements.
     if (mStyleContextGeneration == currentGeneration &&
         mElement->IsInComposedDoc()) {
       // Our cached style context is still valid.
@@ -1619,6 +1619,16 @@ nsComputedDOMStyle::DoGetFontFeatureSettings()
   return val.forget();
 }
 
+already_AddRefed<CSSValue>
+nsComputedDOMStyle::DoGetFontVariationSettings()
+{
+  // TODO: This is still a stub, always returning "normal"
+  RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+
+  val->SetIdent(eCSSKeyword_normal);
+  return val.forget();
+}
+
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetFontKerning()
 {
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 7fbf49afe7..e94d8dbf64 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -251,6 +251,7 @@ private:
   already_AddRefed<CSSValue> DoGetColor();
   already_AddRefed<CSSValue> DoGetFontFamily();
   already_AddRefed<CSSValue> DoGetFontFeatureSettings();
+  already_AddRefed<CSSValue> DoGetFontVariationSettings();
   already_AddRefed<CSSValue> DoGetFontKerning();
   already_AddRefed<CSSValue> DoGetFontLanguageOverride();
   already_AddRefed<CSSValue> DoGetFontSize();
diff --git a/layout/style/nsComputedDOMStylePropertyList.h b/layout/style/nsComputedDOMStylePropertyList.h
index 825976b583..5572818105 100644
--- a/layout/style/nsComputedDOMStylePropertyList.h
+++ b/layout/style/nsComputedDOMStylePropertyList.h
@@ -144,6 +144,7 @@ COMPUTED_STYLE_PROP(font_variant_east_asian,       FontVariantEastAsian)
 COMPUTED_STYLE_PROP(font_variant_ligatures,        FontVariantLigatures)
 COMPUTED_STYLE_PROP(font_variant_numeric,          FontVariantNumeric)
 COMPUTED_STYLE_PROP(font_variant_position,         FontVariantPosition)
+COMPUTED_STYLE_PROP(font_variation_settings,       FontVariationSettings)
 COMPUTED_STYLE_PROP(font_weight,                   FontWeight)
 COMPUTED_STYLE_PROP(grid_auto_columns,             GridAutoColumns)
 COMPUTED_STYLE_PROP(grid_auto_flow,                GridAutoFlow)
diff --git a/layout/tables/nsTableFrame.cpp b/layout/tables/nsTableFrame.cpp
index 0e54fd093e..868f83bda2 100644
--- a/layout/tables/nsTableFrame.cpp
+++ b/layout/tables/nsTableFrame.cpp
@@ -1237,19 +1237,29 @@ PaintRowGroupBackgroundByColIdx(nsTableRowGroupFrame* aRowGroup,
                                 const nsTArray<int32_t>& aColIdx,
                                 const nsPoint& aOffset)
 {
+  MOZ_DIAGNOSTIC_ASSERT(!aColIdx.IsEmpty(),
+                        "Must be painting backgrounds for something");
   for (nsTableRowFrame* row = aRowGroup->GetFirstRow(); row; row = row->GetNextRow()) {
     auto rowPos = row->GetNormalPosition() + aOffset;
     if (!aDirtyRect.Intersects(nsRect(rowPos, row->GetSize()))) {
       continue;
     }
     for (nsTableCellFrame* cell = row->GetFirstCell(); cell; cell = cell->GetNextCell()) {
+
+      int32_t curColIdx;
+      cell->GetColIndex(curColIdx);
+      if (!aColIdx.Contains(curColIdx)) {
+        if (curColIdx > aColIdx.LastElement()) {
+          // We can just stop looking at this row.
+          break;
+        }
+        continue;
+      }
+
       if (!cell->ShouldPaintBackground(aBuilder)) {
         continue;
       }
 
-      int32_t curColIdx;
-      cell->GetColIndex(curColIdx);
-      if (aColIdx.Contains(curColIdx)) {
         auto cellPos = cell->GetNormalPosition() + rowPos;
         auto cellRect = nsRect(cellPos, cell->GetSize());
         if (!aDirtyRect.Intersects(cellRect)) {
@@ -1260,7 +1270,6 @@ PaintRowGroupBackgroundByColIdx(nsTableRowGroupFrame* aRowGroup,
                                                              true, nullptr,
                                                              aFrame->GetRectRelativeToSelf(),
                                                              cell);
-      }
     }
   }
 }
@@ -1311,18 +1320,23 @@ nsTableFrame::DisplayGenericTablePart(nsDisplayListBuilder* aBuilder,
     // Collecting column index.
     AutoTArray<int32_t, 1> colIdx;
     for (nsTableColFrame* col = colGroup->GetFirstColumn(); col; col = col->GetNextCol()) {
+      MOZ_ASSERT(colIdx.IsEmpty() ||
+                 col->GetColIndex() > colIdx.LastElement());
       colIdx.AppendElement(col->GetColIndex());
     }
 
-    nsTableFrame* table = colGroup->GetTableFrame();
-    RowGroupArray rowGroups;
-    table->OrderRowGroups(rowGroups);
-    for (nsTableRowGroupFrame* rowGroup : rowGroups) {
-      auto offset = rowGroup->GetNormalPosition() - colGroup->GetNormalPosition();
-      if (!aDirtyRect.Intersects(nsRect(offset, rowGroup->GetSize()))) {
-        continue;
-      }
+    if (!colIdx.IsEmpty()) {
+      // We have some actual cells that live inside this rowgroup.
+      nsTableFrame* table = colGroup->GetTableFrame();
+      RowGroupArray rowGroups;
+      table->OrderRowGroups(rowGroups);
+      for (nsTableRowGroupFrame* rowGroup : rowGroups) {
+        auto offset = rowGroup->GetNormalPosition() - colGroup->GetNormalPosition();
+        if (!aDirtyRect.Intersects(nsRect(offset, rowGroup->GetSize()))) {
+          continue;
+        }
       PaintRowGroupBackgroundByColIdx(rowGroup, aFrame, aBuilder, aLists, aDirtyRect, colIdx, offset);
+      }
     }
   } else if (aFrame->GetType() == nsGkAtoms::tableColFrame) {
     // Compute background rect by iterating all cell frame.
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 2d9dae7cec..d695a6adcc 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2528,6 +2528,9 @@ pref("layout.css.image-orientation.enabled", true);
 // Is support for the font-display @font-face descriptor enabled?
 pref("layout.css.font-display.enabled", false);
 
+// Enable the font variation stub code?
+pref("layout.css.font-variations.stub", true);
+
 // Are sets of prefixed properties supported?
 pref("layout.css.prefixes.border-image", true);
 pref("layout.css.prefixes.transforms", true);
diff --git a/toolkit/mozapps/downloads/nsHelperAppDlg.js b/toolkit/mozapps/downloads/nsHelperAppDlg.js
index 52d8b4f900..90d38c90b0 100644
--- a/toolkit/mozapps/downloads/nsHelperAppDlg.js
+++ b/toolkit/mozapps/downloads/nsHelperAppDlg.js
@@ -638,6 +638,7 @@ nsUnknownContentTypeDialog.prototype = {
 
   // Returns true if opening the default application makes sense.
   openWithDefaultOK: function() {
+    // The checking is different on Windows...
 #ifdef XP_WIN
     // Windows presents some special cases.
     // We need to prevent use of "system default" when the file is
@@ -675,7 +676,7 @@ nsUnknownContentTypeDialog.prototype = {
   // getPath:
   getPath: function (aFile) {
 #ifdef XP_MACOSX
-    return aFile.leafName || aFile.path;
+      return aFile.leafName || aFile.path;
 #else
     return aFile.path;
 #endif
@@ -1007,11 +1008,13 @@ nsUnknownContentTypeDialog.prototype = {
       var otherHandler = this.dialogElement("otherHandler");
       otherHandler.removeAttribute("hidden");
       otherHandler.setAttribute("path", this.getPath(this.chosenApp.executable));
+
 #ifdef XP_WIN
       otherHandler.label = this.getFileDisplayName(this.chosenApp.executable);
 #else
       otherHandler.label = this.chosenApp.name;
 #endif
+
       this.dialogElement("openHandler").selectedIndex = 1;
       this.dialogElement("openHandler").setAttribute("lastSelectedItemID", "otherHandler");
 
@@ -1069,40 +1072,40 @@ nsUnknownContentTypeDialog.prototype = {
       // Remember the file they chose to run.
       this.chosenApp = params.handlerApp;
     }
-#else
+#else // XP_WIN
 #if MOZ_WIDGET_GTK == 3
-      var nsIApplicationChooser = Components.interfaces.nsIApplicationChooser;
-      var appChooser = Components.classes["@mozilla.org/applicationchooser;1"]
-                                 .createInstance(nsIApplicationChooser);
-      appChooser.init(this.mDialog, this.dialogElement("strings").getString("chooseAppFilePickerTitle"));
-      var contentTypeDialogObj = this;
-      let appChooserCallback = function appChooserCallback_done(aResult) {
-        if (aResult) {
-           contentTypeDialogObj.chosenApp = aResult.QueryInterface(Components.interfaces.nsILocalHandlerApp);
-        }
-        contentTypeDialogObj.finishChooseApp();
-      };
-      appChooser.open(this.mLauncher.MIMEInfo.MIMEType, appChooserCallback);
-      // The finishChooseApp is called from appChooserCallback
-      return;
-#else
-      var nsIFilePicker = Components.interfaces.nsIFilePicker;
-      var fp = Components.classes["@mozilla.org/filepicker;1"]
-                         .createInstance(nsIFilePicker);
-      fp.init(this.mDialog,
-              this.dialogElement("strings").getString("chooseAppFilePickerTitle"),
-              nsIFilePicker.modeOpen);
-
-      fp.appendFilters(nsIFilePicker.filterApps);
-
-      if (fp.show() == nsIFilePicker.returnOK && fp.file) {
-        // Remember the file they chose to run.
-        var localHandlerApp =
-          Components.classes["@mozilla.org/uriloader/local-handler-app;1"].
-                     createInstance(Components.interfaces.nsILocalHandlerApp);
-        localHandlerApp.executable = fp.file;
-        this.chosenApp = localHandlerApp;
+    var nsIApplicationChooser = Components.interfaces.nsIApplicationChooser;
+    var appChooser = Components.classes["@mozilla.org/applicationchooser;1"]
+                               .createInstance(nsIApplicationChooser);
+    appChooser.init(this.mDialog, this.dialogElement("strings").getString("chooseAppFilePickerTitle"));
+    var contentTypeDialogObj = this;
+    let appChooserCallback = function appChooserCallback_done(aResult) {
+      if (aResult) {
+         contentTypeDialogObj.chosenApp = aResult.QueryInterface(Components.interfaces.nsILocalHandlerApp);
       }
+      contentTypeDialogObj.finishChooseApp();
+    };
+    appChooser.open(this.mLauncher.MIMEInfo.MIMEType, appChooserCallback);
+    // The finishChooseApp is called from appChooserCallback
+    return;
+#else // MOZ_WIDGET_GTK == 3
+    var nsIFilePicker = Components.interfaces.nsIFilePicker;
+    var fp = Components.classes["@mozilla.org/filepicker;1"]
+                       .createInstance(nsIFilePicker);
+    fp.init(this.mDialog,
+            this.dialogElement("strings").getString("chooseAppFilePickerTitle"),
+            nsIFilePicker.modeOpen);
+
+    fp.appendFilters(nsIFilePicker.filterApps);
+
+    if (fp.show() == nsIFilePicker.returnOK && fp.file) {
+      // Remember the file they chose to run.
+      var localHandlerApp =
+        Components.classes["@mozilla.org/uriloader/local-handler-app;1"].
+                   createInstance(Components.interfaces.nsILocalHandlerApp);
+      localHandlerApp.executable = fp.file;
+      this.chosenApp = localHandlerApp;
+    }
 #endif // MOZ_WIDGET_GTK == 3
 #endif // XP_WIN
     this.finishChooseApp();