Open Radar

 
Summary:
Mobile Safari crashes or reloads the page showing "A problem occurred with this webpage so it was reloaded". when the user takes a photo after tapping on a HTML file input.

Steps to Reproduce:
1. Open a few other tabs with relatively heavy websites (NYTimes, Guardian, CNN, BBC, Adobe, Google image search)
2. Open a website with a file upload on it
3. Select "Choose file"
4. Select "Take Picture" from the action sheet

Expected Results:
The selected file should populate the input field without crashing the tab/browser.

Actual Results:
Sometimes the website reloads and shows "A problem occurred with this webpage so it was reloaded" in the banner at the top. On a few occasions we've seen Mobile Safari crashing completely, not just reloading the current tap.

Version:
iOS 8.2 (12D508)

Notes:
The behaviour is more likely to happen the more memory is used by a website and other tabs. However, at the same time, we tried reducing the memory footprint of our website and it doesn't make much of a difference.

I don't know if it's relevant but we also use a few CSS transitions.

We tried building an isolated case to showcase the behaviour. However with a lot less CSS and Javascript it doesn't cause the crash/reload.

Also, trying the same on other devices it seems to be only happening on iPhone 6.

Configuration:
iPhone 6, 64GB, O2 UK, using WiFi


The crash log shows:

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Subtype: KERN_INVALID_ADDRESS at 0x0004000000000368
Triggered by Thread:  0

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   WebKit                        	0x000000018a775e94 WebKit::WebPageProxy::didChooseFilesForOpenPanelWithDisplayStringAndIcon(WTF::Vector<WTF::String, 0ul, WTF::CrashOnOverflow> const&, WTF::String const&, API::Data const*) + 44
1   WebKit                        	0x000000018a751de4 WebKit::WebOpenPanelResultListenerProxy::chooseFiles(API::Array*, API::String*, API::Data const*) + 100
2   WebKit                        	0x000000018a751de4 WebKit::WebOpenPanelResultListenerProxy::chooseFiles(API::Array*, API::String*, API::Data const*) + 100
3   WebKit                        	0x000000018a70357c -[WKFileUploadPanel _chooseFiles:displayString:iconImage:] + 468
4   libdispatch.dylib             	0x0000000196a0d990 _dispatch_call_block_and_release + 20
5   libdispatch.dylib             	0x0000000196a0d950 _dispatch_client_callout + 12
6   libdispatch.dylib             	0x0000000196a12208 _dispatch_main_queue_callback_4CF + 1604
7   CoreFoundation                	0x000000018539e2e8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
8   CoreFoundation                	0x000000018539c390 __CFRunLoopRun + 1488
9   CoreFoundation                	0x00000001852c91f0 CFRunLoopRunSpecific + 392
10  GraphicsServices              	0x000000018e6eb6f8 GSEventRunModal + 164
11  UIKit                         	0x0000000189c5a108 UIApplicationMain + 1484
12  MobileSafari                  	0x000000010006b494 0x100064000 + 29844
13  libdyld.dylib                 	0x0000000196a3aa04 start + 0