From 94f3f356ed710e88753ce6a92f1ba8eab3fe9da7 Mon Sep 17 00:00:00 2001
From: Moonchild <moonchild@palemoon.org>
Date: Sat, 15 Jan 2022 21:31:29 +0000
Subject: [PATCH] Issue #3050 - Follow-up: extend attribution mapping to resize
 and corner controls to allow themes to respond to scrollbar-width.

Also clean up the comments and whitespace a bit.
---
 layout/generic/nsGfxScrollFrame.cpp | 33 +++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/layout/generic/nsGfxScrollFrame.cpp b/layout/generic/nsGfxScrollFrame.cpp
index e1a7215d93..8e887f9389 100644
--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -4474,7 +4474,8 @@ ScrollFrameHelper::CreateAnonymousContent(
                                 NS_LITERAL_STRING("horizontal"), false);
     mHScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::clickthrough,
                                 NS_LITERAL_STRING("always"), false);
-    // Map scrollbar-width to an attribute for browser themes.
+
+    // Map scrollbar-width to an attribute on horizontal scrollbars for browser themes.
     if (scrollWidth == StyleScrollbarWidth::None) {
       mHScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
                                   NS_LITERAL_STRING("none"), false);
@@ -4485,6 +4486,7 @@ ScrollFrameHelper::CreateAnonymousContent(
       mHScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
                                   NS_LITERAL_STRING("auto"), false);
     }
+
     if (mIsRoot) {
       mHScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::root_,
                                   NS_LITERAL_STRING("true"), false);
@@ -4508,7 +4510,8 @@ ScrollFrameHelper::CreateAnonymousContent(
                                 NS_LITERAL_STRING("vertical"), false);
     mVScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::clickthrough,
                                 NS_LITERAL_STRING("always"), false);
-    // Map scrollbar-width to an attribute for browser themes.
+
+    // Map scrollbar-width to an attribute on vertical scrollbars for browser themes.
     if (scrollWidth == StyleScrollbarWidth::None) {
       mVScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
                                   NS_LITERAL_STRING("none"), false);
@@ -4519,6 +4522,7 @@ ScrollFrameHelper::CreateAnonymousContent(
       mVScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
                                   NS_LITERAL_STRING("auto"), false);
     }
+
     if (mIsRoot) {
       mVScrollbarContent->SetAttr(kNameSpaceID_None, nsGkAtoms::root_,
                                   NS_LITERAL_STRING("true"), false);
@@ -4557,6 +4561,18 @@ ScrollFrameHelper::CreateAnonymousContent(
     }
     mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::dir, dir, false);
 
+    // Map scrollbar-width to an attribute on resizers for browser themes.
+    if (scrollWidth == StyleScrollbarWidth::None) {
+      mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                               NS_LITERAL_STRING("none"), false);
+    } else if (scrollWidth == StyleScrollbarWidth::Thin) {
+      mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                               NS_LITERAL_STRING("thin"), false);
+    } else {
+      mResizerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                               NS_LITERAL_STRING("auto"), false);
+    }
+
     if (mIsRoot) {
       nsIContent* browserRoot = GetBrowserRoot(mOuter->GetContent());
       mCollapsedResizer = !(browserRoot &&
@@ -4579,6 +4595,19 @@ ScrollFrameHelper::CreateAnonymousContent(
                                             kNameSpaceID_XUL,
                                             nsIDOMNode::ELEMENT_NODE);
     NS_TrustedNewXULElement(getter_AddRefs(mScrollCornerContent), nodeInfo.forget());
+    
+    // Map scrollbar-width to an attribute on scrollcorners for browser themes.
+    if (scrollWidth == StyleScrollbarWidth::None) {
+      mScrollCornerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                                  NS_LITERAL_STRING("none"), false);
+    } else if (scrollWidth == StyleScrollbarWidth::Thin) {
+      mScrollCornerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                                  NS_LITERAL_STRING("thin"), false);
+    } else {
+      mScrollCornerContent->SetAttr(kNameSpaceID_None, nsGkAtoms::scrollbarwidth,
+                                  NS_LITERAL_STRING("auto"), false);
+    }
+
     if (!aElements.AppendElement(mScrollCornerContent))
       return NS_ERROR_OUT_OF_MEMORY;
   }