diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index ab4c8ef..d6dd108 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,40 @@
+2020-01-17  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        Make pasteboard markup sanitization more robust
+        https://bugs.webkit.org/show_bug.cgi?id=206379
+        <rdar://problem/58660859>
+
+        Reviewed by Ryosuke Niwa.
+
+        Makes markup sanitization when copying and pasting more robust in some circumstances (see the bug for additional
+        details).
+
+        * editing/markup.cpp:
+        (WebCore::createPageForSanitizingWebContent):
+
+        Adopt the new setting when creating the temporary web page used to sanitize markup coming from the pasteboard.
+
+        * html/parser/HTMLParserOptions.cpp:
+        (WebCore::HTMLParserOptions::HTMLParserOptions):
+        * html/parser/HTMLParserOptions.h:
+
+        Rename `scriptEnabled` to `scriptingFlag`, since parsing script elements may now be allowed even when JavaScript
+        execution is disabled. The term "scripting flag" also closely matches the wording of the HTML parsing
+        specification.
+
+        * html/parser/HTMLTokenizer.cpp:
+        (WebCore::HTMLTokenizer::updateStateFor):
+        * html/parser/HTMLTreeBuilder.cpp:
+        (WebCore::HTMLTreeBuilder::processStartTagForInBody):
+        (WebCore::HTMLTreeBuilder::processStartTagForInHead):
+        * page/Settings.yaml:
+
+        Add a new setting to determine whether to consider the scripting flag on when parsing HTML. By default, we will
+        only turn the scripting flag on if script execution is enabled; however, this may be set such that we may
+        consider the scripting flag set, even though script execution is disabled.
+
+        * page/SettingsBase.h:
+
 2020-01-18  Antti Koivisto  <antti@apple.com>
 
         [LFC] LayoutState constructor shouldn't take LayoutTreeContent
diff --git a/Source/WebCore/editing/markup.cpp b/Source/WebCore/editing/markup.cpp
index 46458ae..1595035 100644
--- a/Source/WebCore/editing/markup.cpp
+++ b/Source/WebCore/editing/markup.cpp
@@ -181,6 +181,7 @@
     auto page = makeUnique<Page>(WTFMove(pageConfiguration));
     page->settings().setMediaEnabled(false);
     page->settings().setScriptEnabled(false);
+    page->settings().setParserScriptingFlagPolicy(SettingsBase::ParserScriptingFlagPolicy::Enabled);
     page->settings().setPluginsEnabled(false);
     page->settings().setAcceleratedCompositingEnabled(false);
 
diff --git a/Source/WebCore/html/parser/HTMLParserOptions.cpp b/Source/WebCore/html/parser/HTMLParserOptions.cpp
index f82eb0a..58d95ca 100644
--- a/Source/WebCore/html/parser/HTMLParserOptions.cpp
+++ b/Source/WebCore/html/parser/HTMLParserOptions.cpp
@@ -36,7 +36,7 @@
 namespace WebCore {
 
 HTMLParserOptions::HTMLParserOptions()
-    : scriptEnabled(false)
+    : scriptingFlag(false)
     , usePreHTML5ParserQuirks(false)
     , maximumDOMTreeDepth(Settings::defaultMaximumHTMLParserDOMTreeDepth)
 {
@@ -45,7 +45,10 @@
 HTMLParserOptions::HTMLParserOptions(Document& document)
 {
     RefPtr<Frame> frame = document.frame();
-    scriptEnabled = frame && frame->script().canExecuteScripts(NotAboutToExecuteScript);
+    if (document.settings().parserScriptingFlagPolicy() == SettingsBase::ParserScriptingFlagPolicy::Enabled)
+        scriptingFlag = true;
+    else
+        scriptingFlag = frame && frame->script().canExecuteScripts(NotAboutToExecuteScript);
 
     usePreHTML5ParserQuirks = document.settings().usePreHTML5ParserQuirks();
     maximumDOMTreeDepth = document.settings().maximumHTMLParserDOMTreeDepth();
diff --git a/Source/WebCore/html/parser/HTMLParserOptions.h b/Source/WebCore/html/parser/HTMLParserOptions.h
index f205526..50bfa60 100644
--- a/Source/WebCore/html/parser/HTMLParserOptions.h
+++ b/Source/WebCore/html/parser/HTMLParserOptions.h
@@ -34,7 +34,8 @@
     explicit HTMLParserOptions();
     explicit HTMLParserOptions(Document&);
 
-    bool scriptEnabled;
+    // See https://html.spec.whatwg.org/#scripting-flag for more information.
+    bool scriptingFlag;
     bool usePreHTML5ParserQuirks;
     unsigned maximumDOMTreeDepth;
 };
diff --git a/Source/WebCore/html/parser/HTMLTokenizer.cpp b/Source/WebCore/html/parser/HTMLTokenizer.cpp
index aa75adc..d3eba51 100644
--- a/Source/WebCore/html/parser/HTMLTokenizer.cpp
+++ b/Source/WebCore/html/parser/HTMLTokenizer.cpp
@@ -1418,7 +1418,7 @@
         || tagName == xmpTag
         || (tagName == noembedTag)
         || tagName == noframesTag
-        || (tagName == noscriptTag && m_options.scriptEnabled))
+        || (tagName == noscriptTag && m_options.scriptingFlag))
         m_state = RAWTEXTState;
 }
 
diff --git a/Source/WebCore/html/parser/HTMLTreeBuilder.cpp b/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
index 7867c28..b1930e4 100644
--- a/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
+++ b/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
@@ -791,7 +791,7 @@
         processGenericRawTextStartTag(WTFMove(token));
         return;
     }
-    if (token.name() == noscriptTag && m_options.scriptEnabled) {
+    if (token.name() == noscriptTag && m_options.scriptingFlag) {
         processGenericRawTextStartTag(WTFMove(token));
         return;
     }
@@ -2608,7 +2608,7 @@
         return true;
     }
     if (token.name() == noscriptTag) {
-        if (m_options.scriptEnabled) {
+        if (m_options.scriptingFlag) {
             processGenericRawTextStartTag(WTFMove(token));
             return true;
         }
diff --git a/Source/WebCore/page/Settings.yaml b/Source/WebCore/page/Settings.yaml
index 887559c..50d2340 100644
--- a/Source/WebCore/page/Settings.yaml
+++ b/Source/WebCore/page/Settings.yaml
@@ -731,6 +731,9 @@
   initial: false
   getter: isScriptEnabled
   inspectorOverride: true
+parserScriptingFlagPolicy:
+  type: ParserScriptingFlagPolicy
+  initial: ParserScriptingFlagPolicy::OnlyIfScriptIsEnabled
 pluginsEnabled:
   initial: false
   getter: arePluginsEnabled
diff --git a/Source/WebCore/page/SettingsBase.h b/Source/WebCore/page/SettingsBase.h
index f1a65f6..251b7e6 100644
--- a/Source/WebCore/page/SettingsBase.h
+++ b/Source/WebCore/page/SettingsBase.h
@@ -104,6 +104,7 @@
     void pageDestroyed() { m_page = nullptr; }
 
     enum class FontLoadTimingOverride { None, Block, Swap, Failure };
+    enum class ParserScriptingFlagPolicy : uint8_t { OnlyIfScriptIsEnabled, Enabled };
 
     // FIXME: Move these default values to SettingsDefaultValues.h