[TIMOB-4751] Random crash using getElementsByTagName to parse XML

GitHub Issue	n/a
Type	Bug
Priority	Critical
Status	Closed
Resolution	Cannot Reproduce
Resolution Date	2011-08-01T11:54:31.000+0000
Affected Version/s	n/a
Fix Version/s	Sprint 2011-31
Components	iOS
Labels	bad_access, callback, xmlparsing
Reporter	Davide Bertola
Assignee	Blain Hamon
Created	2011-07-20T05:10:22.000+0000
Updated	2012-02-09T14:02:43.000+0000

Description

Attachments

File	Date	Size
stacktrace.txt	2011-07-21T02:50:43.000+0000	1590

Comments

Davide Bertola 2011-07-22

I don't know if it's useful but we discovered that we can workaround the crash rewriting the code like this

   Titanium.UI.setBackgroundColor('#000');
   
   var app = {};
   
   var win = Ti.UI.createWindow({
   	title: "Nope"
   });
   
   var test = Ti.XML.parseString ("<stops><lat>ciao</lat></stops>");
   var result = [];
   function crashIt () {
   	for (var i=0; i<1000; i++) {
   		setTimeout (function () {
   			var foo = test.getElementsByTagName ("lat").item (0).text;
   			result.push (i + " - " + foo);
   		}, 1);
   	}
   }
   crashIt ();
   
   //Ti.API.debug (result);
   
   win.open ();

Davide Bertola 2011-07-22

inside KrollObject, in function ConvertIdTiValue around line 266 we have

   	else if ([obj isKindOfClass:[KrollMethod class]])
   	{
   		KrollContext * ourContext = [(KrollMethod *)obj context];
   		if (context == ourContext)
   		{
   			return [(KrollMethod *)obj jsobject];
   		}
   		return TiObjectMake(jsContext,KrollMethodClassRef,obj);
   	}

disabling the internal IF seems to fix the crash, but don't know why

   	else if ([obj isKindOfClass:[KrollMethod class]])
   	{
   		KrollContext * ourContext = [(KrollMethod *)obj context];
   		if (context == ourContext && 0)
   		{
   			return [(KrollMethod *)obj jsobject];
   		}
   		return TiObjectMake(jsContext,KrollMethodClassRef,obj);
   	}

I hope this helps

Eduardo Gomez 2011-07-27

Associated HD ticket

A PRO customer relies on this, http://appc.me/c/APP-414331

Repro sequence

Once this snippet code starts working and parsing XML data, occasionally app crashes.

   var xhr = Ti.Network.createHTTPClient();
   xhr.open("GET","http://v2.0.news.tmg.s3.amazonaws.com/feeds/news.xml");
               xhr.onload = function()
               {
                   try 
                   {
                       var doc = this.responseXML.documentElement;
                       var items = doc.getElementsByTagName("item");
                       var x = 0;
                       var doctitle = doc.evaluate("//channel/title/text()").item(0).nodeValue;
   
   
   
                       for (var c=0, l=items.length;c<l;c++)               
                           {
                           var item = items.item(c);
   
                               var elemTitle = item.getElementsByTagName("title").item(0).text;
                               Ti.API.info('-> '+elemTitle);
   
                               var elemUrl = item.getElementsByTagName("link").item(0).text;
                                        Ti.API.info('-> '+elemUrl);
                               //Get and format the date
   
                               var origDate = item.getElementsByTagName("pubDate").item(0).text;   
   
                               var date_arr = origDate.split(" ");
   
                               var elemDate = date_arr[2]+" "+date_arr[1]+", "+date_arr[3];
   
                               //Push to the array
                               articlesData.push({
                                   title:elemTitle,
                                   url:elemUrl,
                                   date:elemDate
                               });
   
                           }
                           Ti.App.Properties.setList('articlesProp', articlesData);
   
                   }
                   catch(E)
                   {
                       alert(E);
                   }
               };
   
           xhr.send();

Blain Hamon 2011-08-01

As of Aug 1, could not crash on device or simulator. Given the crash log given, it's highly likely that this was fixed by the new TiJSCore update that happened recently.
Thomas Huelbert 2012-02-09

closing as we are not able to reproduce using master (1.9.0 Feb 9 2012 09:46 rd47ce8a4)

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