Download all attachments doesn't work if the attachment name has a ':' sign

Summary of bug

When trying to use the 'download all attachments' link, if one of the name of the attachments contain a ':' sign, then the download will fail, and an error page will be shown.

Steps to reproduce

1. Create a page in Confluence
2. Attach an attachment that has the ':' sign in the file name. (To do so, you might have to print screen and directly paste it into the Confluence page)
3. Once attached, save the page
4. Access the Attachments menu, and try to use the 'Download All' button. The following error page will appear :

Additional Info

• The following stack trace appears as well :

  java.io.FileNotFoundException: C:\Home Directories\Confluence 5.3\temp\downloadIA7uN190218\image2014-1-24 19:0:54.png (The filename, directory name, or volume label syntax is incorrect)
  	at java.io.FileOutputStream.open(Native Method)
  	at java.io.FileOutputStream.<init>(FileOutputStream.java:194)
  	at java.io.FileOutputStream.<init>(FileOutputStream.java:145)
  	at com.atlassian.confluence.pages.actions.DownloadAllAttachmentsOnPageAction.execute(DownloadAllAttachmentsOnPageAction.java:43)
  	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:168)
  	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:35)
  	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)
  	at com.atlassian.confluence.core.ConfluenceWorkflowInterceptor.intercept(ConfluenceWorkflowInterceptor.java:64)
  	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)
  
  ...
  
  at 
  org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
  	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
  	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
  	at java.lang.Thread.run(Thread.java:662)