From 4744674e933ebbd294878b60c93732500fd4217a Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Mon, 29 Aug 2022 14:53:24 +0200
Subject: [PATCH] fix: crash when switching origins with emulation settings set
 (#35466)

---
 patches/chromium/.patches                     |  1 +
 ...ler_update_functions_to_early_return.patch | 45 +++++++++++++++++++
 spec/api-web-contents-spec.ts                 | 30 +++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 patches/chromium/fix_revert_emulationhandler_update_functions_to_early_return.patch

diff --git a/patches/chromium/.patches b/patches/chromium/.patches
index 485f18915fba..d53c82faf37f 100644
--- a/patches/chromium/.patches
+++ b/patches/chromium/.patches
@@ -117,3 +117,4 @@ add_maximized_parameter_to_linuxui_getwindowframeprovider.patch
 revert_spellcheck_fully_launch_spell_check_delayed_initialization.patch
 add_electron_deps_to_license_credits_file.patch
 feat_add_set_can_resize_mutator.patch
+fix_revert_emulationhandler_update_functions_to_early_return.patch
diff --git a/patches/chromium/fix_revert_emulationhandler_update_functions_to_early_return.patch b/patches/chromium/fix_revert_emulationhandler_update_functions_to_early_return.patch
new file mode 100644
index 000000000000..7a34a6850465
--- /dev/null
+++ b/patches/chromium/fix_revert_emulationhandler_update_functions_to_early_return.patch
@@ -0,0 +1,45 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Shelley Vohr <shelley.vohr@gmail.com>
+Date: Fri, 26 Aug 2022 11:24:27 +0200
+Subject: fix: revert EmulationHandler update functions to early return
+
+Our debugger class (a subclass of ontent::DevToolsAgentHostClient) isn't
+aware of those changes unless we hook RenderFrameHostChanged. If we
+don't do this, some navigation lifecycle events
+{loadingFinished, dataReceived} emitted by the renderer are lost. We
+disconnect and reconnect the webcontents to the DevToolsAgentHost to
+prevent this from happening.
+
+As of https://chromium-review.googlesource.com/c/chromium/src/+/3758294
+this results in a DCHECK, since DevToolsAgentHost::DisconnectWebContents
+results in a call to UpdateDeviceEmulationState and host_ is nullptr. To
+fix this, we revert those state update calls to early returns.
+
+Upstreamed at https://chromium-review.googlesource.com/c/chromium/src/+/3856525
+
+diff --git a/content/browser/devtools/protocol/emulation_handler.cc b/content/browser/devtools/protocol/emulation_handler.cc
+index 84736afeb21d1deec0f4032ef6f3304075d8fffb..d023bb7b5a34c5c055d3d7cc5dc3e04ef43bcc3b 100644
+--- a/content/browser/devtools/protocol/emulation_handler.cc
++++ b/content/browser/devtools/protocol/emulation_handler.cc
+@@ -565,7 +565,9 @@ WebContentsImpl* EmulationHandler::GetWebContents() {
+ }
+ 
+ void EmulationHandler::UpdateTouchEventEmulationState() {
+-  DCHECK(host_);
++  if (!host_)
++    return;
++
+   // We only have a single TouchEmulator for all frames, so let the main frame's
+   // EmulationHandler enable/disable it.
+   DCHECK(!host_->GetParentOrOuterDocument());
+@@ -585,7 +587,9 @@ void EmulationHandler::UpdateTouchEventEmulationState() {
+ }
+ 
+ void EmulationHandler::UpdateDeviceEmulationState() {
+-  DCHECK(host_);
++  if (!host_)
++    return;
++
+   // Device emulation only happens on the outermost main frame.
+   DCHECK(!host_->GetParentOrOuterDocument());
+ 
diff --git a/spec/api-web-contents-spec.ts b/spec/api-web-contents-spec.ts
index f64170592822..3ceb081c76c9 100644
--- a/spec/api-web-contents-spec.ts
+++ b/spec/api-web-contents-spec.ts
@@ -326,6 +326,7 @@ describe('webContents module', () => {
 
   describe('loadURL() promise API', () => {
     let w: BrowserWindow;
+
     beforeEach(async () => {
       w = new BrowserWindow({ show: false });
     });
@@ -357,6 +358,35 @@ describe('webContents module', () => {
         .and.have.property('code', 'ERR_FAILED');
     });
 
+    it('does not crash when loading a new URL with emulation settings set', async () => {
+      const setEmulation = async () => {
+        if (w.webContents) {
+          w.webContents.debugger.attach('1.3');
+
+          const deviceMetrics = {
+            width: 700,
+            height: 600,
+            deviceScaleFactor: 2,
+            mobile: true,
+            dontSetVisibleSize: true
+          };
+          await w.webContents.debugger.sendCommand(
+            'Emulation.setDeviceMetricsOverride',
+            deviceMetrics
+          );
+        }
+      };
+
+      try {
+        await w.loadURL(`file://${fixturesPath}/pages/blank.html`);
+        await setEmulation();
+        await w.loadURL('data:text/html,<h1>HELLO</h1>');
+        await setEmulation();
+      } catch (e) {
+        expect((e as Error).message).to.match(/Debugger is already attached to the target/);
+      }
+    });
+
     it('sets appropriate error information on rejection', async () => {
       let err: any;
       try {