From c9e6d3de8d48c28ccd095514677152040b2c3b2e Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Thu, 12 Mar 2020 11:20:21 -0700
Subject: [PATCH] fix: crash on invalid zoomFactor

---
 docs/api/web-contents.md                       |  4 +++-
 docs/api/web-frame.md                          |  4 +++-
 shell/browser/api/electron_api_web_contents.cc |  9 ++++++++-
 shell/browser/api/electron_api_web_contents.h  |  2 +-
 shell/renderer/api/electron_api_web_frame.cc   | 10 +++++++++-
 spec-main/api-web-contents-spec.ts             | 13 +++++++++++++
 6 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
index fd2940ea802f5..a44cdf279f6e8 100644
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -1060,11 +1060,13 @@ Returns `Boolean` - Whether audio is currently playing.
 
 #### `contents.setZoomFactor(factor)`
 
-* `factor` Number - Zoom factor.
+* `factor` Double - Zoom factor; default is 1.0.
 
 Changes the zoom factor to the specified factor. Zoom factor is
 zoom percent divided by 100, so 300% = 3.0.
 
+The factor must be greater than 0.0.
+
 #### `contents.getZoomFactor()`
 
 Returns `Number` - the current zoom factor.
diff --git a/docs/api/web-frame.md b/docs/api/web-frame.md
index 779434d086c2b..6d2e5b5fdfcb4 100644
--- a/docs/api/web-frame.md
+++ b/docs/api/web-frame.md
@@ -22,11 +22,13 @@ The `WebFrame` class has the following instance methods:
 
 ### `webFrame.setZoomFactor(factor)`
 
-* `factor` Number - Zoom factor.
+* `factor` Double - Zoom factor; default is 1.0.
 
 Changes the zoom factor to the specified factor. Zoom factor is
 zoom percent divided by 100, so 300% = 3.0.
 
+The factor must be greater than 0.0.
+
 ### `webFrame.getZoomFactor()`
 
 Returns `Number` - The current zoom factor.
diff --git a/shell/browser/api/electron_api_web_contents.cc b/shell/browser/api/electron_api_web_contents.cc
index 8d1fa0f4e6f68..d12a2702a474b 100644
--- a/shell/browser/api/electron_api_web_contents.cc
+++ b/shell/browser/api/electron_api_web_contents.cc
@@ -4,6 +4,7 @@
 
 #include "shell/browser/api/electron_api_web_contents.h"
 
+#include <limits>
 #include <memory>
 #include <set>
 #include <string>
@@ -2489,7 +2490,13 @@ double WebContents::GetZoomLevel() const {
   return zoom_controller_->GetZoomLevel();
 }
 
-void WebContents::SetZoomFactor(double factor) {
+void WebContents::SetZoomFactor(gin_helper::ErrorThrower thrower,
+                                double factor) {
+  if (factor < std::numeric_limits<double>::epsilon()) {
+    thrower.ThrowError("'zoomFactor' must be a double greater than 0.0");
+    return;
+  }
+
   auto level = blink::PageZoomFactorToZoomLevel(factor);
   SetZoomLevel(level);
 }
diff --git a/shell/browser/api/electron_api_web_contents.h b/shell/browser/api/electron_api_web_contents.h
index 84ae2b50036fc..7f32581787dff 100644
--- a/shell/browser/api/electron_api_web_contents.h
+++ b/shell/browser/api/electron_api_web_contents.h
@@ -297,7 +297,7 @@ class WebContents : public gin_helper::TrackableObject<WebContents>,
   // Methods for zoom handling.
   void SetZoomLevel(double level);
   double GetZoomLevel() const;
-  void SetZoomFactor(double factor);
+  void SetZoomFactor(gin_helper::ErrorThrower thrower, double factor);
   double GetZoomFactor() const;
 
   // Callback triggered on permission response.
diff --git a/shell/renderer/api/electron_api_web_frame.cc b/shell/renderer/api/electron_api_web_frame.cc
index 924bddd733224..708b8da95cc45 100644
--- a/shell/renderer/api/electron_api_web_frame.cc
+++ b/shell/renderer/api/electron_api_web_frame.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by the MIT license that can be
 // found in the LICENSE file.
 
+#include <limits>
 #include <memory>
 #include <string>
 #include <utility>
@@ -275,7 +276,14 @@ double GetZoomLevel(v8::Local<v8::Value> window) {
   return result;
 }
 
-void SetZoomFactor(v8::Local<v8::Value> window, double factor) {
+void SetZoomFactor(gin_helper::ErrorThrower thrower,
+                   v8::Local<v8::Value> window,
+                   double factor) {
+  if (factor < std::numeric_limits<double>::epsilon()) {
+    thrower.ThrowError("'zoomFactor' must be a double greater than 0.0");
+    return;
+  }
+
   SetZoomLevel(window, blink::PageZoomFactorToZoomLevel(factor));
 }
 
diff --git a/spec-main/api-web-contents-spec.ts b/spec-main/api-web-contents-spec.ts
index f84631fe98470..80cb0164fe2bc 100644
--- a/spec-main/api-web-contents-spec.ts
+++ b/spec-main/api-web-contents-spec.ts
@@ -846,6 +846,19 @@ describe('webContents module', () => {
 
     afterEach(closeAllWindows)
 
+    it('throws on an invalid zoomFactor', async () => {
+      const w = new BrowserWindow({ show: false })
+      await w.loadURL('about:blank')
+
+      expect(() => {
+        w.webContents.setZoomFactor(0.0)
+      }).to.throw(/'zoomFactor' must be a double greater than 0.0/)
+
+      expect(() => {
+        w.webContents.setZoomFactor(-2.0)
+      }).to.throw(/'zoomFactor' must be a double greater than 0.0/)
+    })
+
     it('can set the correct zoom level (functions)', async () => {
       const w = new BrowserWindow({ show: false })
       try {