Stop evaluating <script>s moved between Documents during fetching

https://bugs.webkit.org/show_bug.cgi?id=202714
<rdar://problem/56208425>

Reviewed by Geoffrey Garen.

LayoutTests/imported/w3c:

Rebaseline WPT tests now that more checks are passing. Note that these checks were already passing in both Firefox and Chrome.

* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-inline-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-inline-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-inline-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-classic-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-module-expected.txt:
* web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-inline-classic-expected.txt:

Source/WebCore:

Stop evaluating <script>s moved between Documents during fetching:
- whatwg/html#2469
- whatwg/html#2673

Both Firefox and Chrome already behave this way.

No new tests, rebaselined existing tests.

* dom/ScriptElement.cpp:
(WebCore::ScriptElement::prepareScript):
Set the element's preparation-time document to its node document, as per:
- https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script (step 11)

(WebCore::ScriptElement::executePendingScript):
If scriptElement's preparation-time document is not equal to scriptElement's node document, then return, as per:
- https://html.spec.whatwg.org/multipage/scripting.html#execute-the-script-block (step 2)

* dom/ScriptElement.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@280924 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/imported/w3c/ChangeLog

@@ -1,3 +1,30 @@
+2021-08-11  Chris Dumez  <cdumez@apple.com>
+
+        Stop evaluating <script>s moved between Documents during fetching
+        https://bugs.webkit.org/show_bug.cgi?id=202714
+        <rdar://problem/56208425>
+
+        Reviewed by Geoffrey Garen.
+
+        Rebaseline WPT tests now that more checks are passing. Note that these checks were already passing in both Firefox and Chrome.
+
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-inline-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-inline-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-inline-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-classic-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-module-expected.txt:
+        * web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-inline-classic-expected.txt:
+
 2021-08-11  Chris Dumez  <cdumez@apple.com>
 
         HTMLMetaElement http-equiv should not be processed in shadow trees

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-classic-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move fetch-error external classic script to iframe after-prepare
 PASS <script> load: Move fetch-error external classic script to iframe after-prepare
-FAIL <script> error: Move fetch-error external classic script to iframe after-prepare assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move fetch-error external classic script to iframe after-prepare
 PASS window error: Move fetch-error external classic script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-fetch-error-external-module-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move fetch-error external module script to iframe after-prepare
 PASS <script> load: Move fetch-error external module script to iframe after-prepare
-FAIL <script> error: Move fetch-error external module script to iframe after-prepare assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move fetch-error external module script to iframe after-prepare
 PASS window error: Move fetch-error external module script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error external classic script to iframe after-prepare
-FAIL <script> load: Move parse-error external classic script to iframe after-prepare assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move parse-error external classic script to iframe after-prepare
 PASS <script> error: Move parse-error external classic script to iframe after-prepare
-FAIL window error: Move parse-error external classic script to iframe after-prepare assert_unreached: Window error event shouldn't fired on destination window Reached unreachable code
+PASS window error: Move parse-error external classic script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-external-module-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error external module script to iframe after-prepare
 PASS <script> load: Move parse-error external module script to iframe after-prepare
-FAIL <script> error: Move parse-error external module script to iframe after-prepare assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move parse-error external module script to iframe after-prepare
 PASS window error: Move parse-error external module script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-parse-error-inline-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error inline classic script to iframe after-prepare
-FAIL <script> load: Move parse-error inline classic script to iframe after-prepare assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move parse-error inline classic script to iframe after-prepare
 PASS <script> error: Move parse-error inline classic script to iframe after-prepare
-FAIL window error: Move parse-error inline classic script to iframe after-prepare assert_unreached: Window error event shouldn't fired on destination window Reached unreachable code
+PASS window error: Move parse-error inline classic script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: exec
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
-FAIL Eval: Move success external classic script to iframe after-prepare assert_false: The script must not have executed in destination window expected false got "executed"
-FAIL <script> load: Move success external classic script to iframe after-prepare assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS Eval: Move success external classic script to iframe after-prepare
+PASS <script> load: Move success external classic script to iframe after-prepare
 PASS <script> error: Move success external classic script to iframe after-prepare
 PASS window error: Move success external classic script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-external-module-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: TypeError: Requested module is not instantiated yet.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move success external module script to iframe after-prepare
-FAIL <script> load: Move success external module script to iframe after-prepare assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move success external module script to iframe after-prepare
 PASS <script> error: Move success external module script to iframe after-prepare
-FAIL window error: Move success external module script to iframe after-prepare assert_unreached: Window error event shouldn't fired on destination window Reached unreachable code
+PASS window error: Move success external module script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/after-prepare-iframe-success-inline-classic-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
-FAIL Eval: Move success inline classic script to iframe after-prepare assert_false: The script must not have executed in destination window expected false got "executed"
-FAIL <script> load: Move success inline classic script to iframe after-prepare assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS Eval: Move success inline classic script to iframe after-prepare
+PASS <script> load: Move success inline classic script to iframe after-prepare
 PASS <script> error: Move success inline classic script to iframe after-prepare
 PASS window error: Move success inline classic script to iframe after-prepare
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-classic-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move fetch-error external classic script to iframe move-back
 PASS <script> load: Move fetch-error external classic script to iframe move-back
-FAIL <script> error: Move fetch-error external classic script to iframe move-back assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move fetch-error external classic script to iframe move-back
 PASS window error: Move fetch-error external classic script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-fetch-error-external-module-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move fetch-error external module script to iframe move-back
 PASS <script> load: Move fetch-error external module script to iframe move-back
-FAIL <script> error: Move fetch-error external module script to iframe move-back assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move fetch-error external module script to iframe move-back
 PASS window error: Move fetch-error external module script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error external classic script to iframe move-back
-FAIL <script> load: Move parse-error external classic script to iframe move-back assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move parse-error external classic script to iframe move-back
 PASS <script> error: Move parse-error external classic script to iframe move-back
-FAIL window error: Move parse-error external classic script to iframe move-back assert_unreached: Window error event shouldn't fired on source window Reached unreachable code
+PASS window error: Move parse-error external classic script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-external-module-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error external module script to iframe move-back
 PASS <script> load: Move parse-error external module script to iframe move-back
-FAIL <script> error: Move parse-error external module script to iframe move-back assert_unreached: Script error evennt fired unexpectedly Reached unreachable code
+PASS <script> error: Move parse-error external module script to iframe move-back
 PASS window error: Move parse-error external module script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-parse-error-inline-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: SyntaxError: Left side of assignment is not a reference.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move parse-error inline classic script to iframe move-back
-FAIL <script> load: Move parse-error inline classic script to iframe move-back assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move parse-error inline classic script to iframe move-back
 PASS <script> error: Move parse-error inline classic script to iframe move-back
-FAIL window error: Move parse-error inline classic script to iframe move-back assert_unreached: Window error event shouldn't fired on source window Reached unreachable code
+PASS window error: Move parse-error inline classic script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-classic-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: exec
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
-FAIL Eval: Move success external classic script to iframe move-back assert_false: The script must not have executed in source window expected false got "executed"
-FAIL <script> load: Move success external classic script to iframe move-back assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS Eval: Move success external classic script to iframe move-back
+PASS <script> load: Move success external classic script to iframe move-back
 PASS <script> error: Move success external classic script to iframe move-back
 PASS window error: Move success external classic script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-external-module-expected.txt

@@ -1,9 +1,9 @@
-CONSOLE MESSAGE: TypeError: Requested module is not instantiated yet.
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
 PASS Eval: Move success external module script to iframe move-back
-FAIL <script> load: Move success external module script to iframe move-back assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS <script> load: Move success external module script to iframe move-back
 PASS <script> error: Move success external module script to iframe move-back
-FAIL window error: Move success external module script to iframe move-back assert_unreached: Window error event shouldn't fired on source window Reached unreachable code
+PASS window error: Move success external module script to iframe move-back
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/scripting-1/the-script-element/moving-between-documents/move-back-iframe-success-inline-classic-expected.txt

@@ -1,8 +1,9 @@
+CONSOLE MESSAGE: Not executing script because it moved between documents during fetching
 
 
 PASS Sanity check around top-level Window
-FAIL Eval: Move success inline classic script to iframe move-back assert_false: The script must not have executed in source window expected false got "executed"
-FAIL <script> load: Move success inline classic script to iframe move-back assert_unreached: Script load event fired unexpectedly Reached unreachable code
+PASS Eval: Move success inline classic script to iframe move-back
+PASS <script> load: Move success inline classic script to iframe move-back
 PASS <script> error: Move success inline classic script to iframe move-back
 PASS window error: Move success inline classic script to iframe move-back
 

Source/WebCore/ChangeLog

@@ -1,3 +1,30 @@
+2021-08-11  Chris Dumez  <cdumez@apple.com>
+
+        Stop evaluating <script>s moved between Documents during fetching
+        https://bugs.webkit.org/show_bug.cgi?id=202714
+        <rdar://problem/56208425>
+
+        Reviewed by Geoffrey Garen.
+
+        Stop evaluating <script>s moved between Documents during fetching:
+        - https://github.com/whatwg/html/issues/2469
+        - https://github.com/whatwg/html/pull/2673
+
+        Both Firefox and Chrome already behave this way.
+
+        No new tests, rebaselined existing tests.
+
+        * dom/ScriptElement.cpp:
+        (WebCore::ScriptElement::prepareScript):
+        Set the element's preparation-time document to its node document, as per:
+        - https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script (step 11)
+
+        (WebCore::ScriptElement::executePendingScript):
+        If scriptElement's preparation-time document is not equal to scriptElement's node document, then return, as per:
+        - https://html.spec.whatwg.org/multipage/scripting.html#execute-the-script-block (step 2)
+
+        * dom/ScriptElement.h:
+
 2021-08-11  Youenn Fablet  <youenn@apple.com>
 
         Media element is not always autoplaying when going from background to foreground if it is initially not in viewport

Source/WebCore/dom/ScriptElement.cpp

@@ -216,6 +216,8 @@ bool ScriptElement::prepareScript(const TextPosition& scriptStartPosition, Legac
     if (scriptType == ScriptType::Classic && hasNoModuleAttribute())
         return false;
 
+    m_preparationTimeDocumentIdentifier = document.identifier();
+
     if (!document.frame()->script().canExecuteScripts(AboutToExecuteScript))
         return false;
 
@@ -451,6 +453,11 @@ void ScriptElement::executeScriptAndDispatchEvent(LoadableScript& loadableScript
 
 void ScriptElement::executePendingScript(PendingScript& pendingScript)
 {
+    if (m_element.document().identifier() != m_preparationTimeDocumentIdentifier) {
+        m_element.document().addConsoleMessage(MessageSource::Security, MessageLevel::Error, "Not executing script because it moved between documents during fetching"_s);
+        return;
+    }
+
     if (auto* loadableScript = pendingScript.loadableScript())
         executeScriptAndDispatchEvent(*loadableScript);
     else {

Source/WebCore/dom/ScriptElement.h

@@ -22,6 +22,7 @@
 #pragma once
 
 #include "ContainerNode.h"
+#include "DocumentIdentifier.h"
 #include "LoadableScript.h"
 #include "ReferrerPolicy.h"
 #include "UserGestureIndicator.h"
@@ -136,6 +137,9 @@ class ScriptElement {
     String m_fallbackCharacterEncoding;
     RefPtr<LoadableScript> m_loadableScript;
 
+    // https://html.spec.whatwg.org/multipage/scripting.html#preparation-time-document
+    DocumentIdentifier m_preparationTimeDocumentIdentifier;
+
     MonotonicTime m_creationTime;
     RefPtr<UserGestureToken> m_userGestureToken;
 };