Issue Collector fails to attach images for anonymous users with error "Cannot attach file image.jpg: Unknown server error (500)."

"Cannot attach file image.jpg: Unknown server error (500)."

2016-07-01 11:09:18,539 http-nio-3004-exec-6 ERROR anonymous 669x6131x1 - 103.233.242.8 /rest/collectors/1.0/tempattachment/1bfd43b8 [c.a.p.r.c.error.jersey.ThrowableExceptionMapper] Uncaught exception thrown by REST service: null
java.lang.NullPointerException
      at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:210)
      at com.atlassian.fugue.Either.right(Either.java:81)
      at com.atlassian.jira.collector.plugin.rest.TemporaryAttachmentsResource.createTemporaryWebAttachment(TemporaryAttachmentsResource.java:187)
      at com.atlassian.jira.collector.plugin.rest.TemporaryAttachmentsResource.addTemporaryWebAttachment(TemporaryAttachmentsResource.java:128)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      ... 2 filtered
      at java.lang.reflect.Method.invoke(Method.java:497)
      ... 19 filtered
      at com.atlassian.plugins.rest.module.RestDelegatingServletFilter$JerseyOsgiServletContainer.doFilter(RestDelegatingServletFilter.java:159)
      ... 1 filtered
      at com.atlassian.plugins.rest.module.RestDelegatingServletFilter.doFilter(RestDelegatingServletFilter.java:69)
      ... 17 filtered
      at com.atlassian.servicedesk.internal.web.OperationalStatusAwareHttpFilter.doFilter(OperationalStatusAwareHttpFilter.java:31)
                                                                                                                                                              1053,1        95%
      ... 17 filtered
      at com.atlassian.servicedesk.internal.web.OperationalStatusAwareHttpFilter.doFilter(OperationalStatusAwareHttpFilter.java:31)
      ... 13 filtered
      at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
      ... 20 filtered
      at com.atlassian.jira.plugins.rest.HOT25715FixServletFilter.doFilter(HOT25715FixServletFilter.java:46)
      ... 25 filtered
      at com.atlassian.plugin.connect.plugin.auth.scope.ApiScopingFilter.doFilter(ApiScopingFilter.java:81)
      ... 14 filtered
      at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:76)
      at com.atlassian.jira.security.JiraSecurityFilter$$Lambda$634/23464434.doFilter(Unknown Source)
      ... 1 filtered
      at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:74)
      ... 16 filtered
      at com.atlassian.plugins.rest.module.servlet.RestSeraphFilter.doFilter(RestSeraphFilter.java:37)
      ... 16 filtered
      at com.atlassian.studio.jira.homepage.CloudHomepageFilter$Action.lambda$nextInFilterChain$1(CloudHomepageFilter.java:110)
      at com.atlassian.studio.jira.homepage.CloudHomepageFilter$Action$$Lambda$627/24218859.execute(Unknown Source)
      at com.atlassian.studio.jira.homepage.CloudHomepageFilter.doFilter(CloudHomepageFilter.java:68)
      ... 17 filtered
      at com.atlassian.jira.servermetrics.CorrelationIdPopulatorFilter.doFilter(CorrelationIdPopulatorFilter.java:30)
      ... 5 filtered
      at com.atlassian.plugin.connect.plugin.auth.user.ThreeLeggedAuthFilter.doFilter(ThreeLeggedAuthFilter.java:109)
      ... 3 filtered
      at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.lambda$invokeFilterChain$0(CustomerContextSettingFilter.java:181)
      at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter$$Lambda$612/13077996.call(Unknown Source)
      at com.atlassian.servicedesk.internal.utils.context.ReentrantThreadLocalBasedCodeContext.rteInvoke(ReentrantThreadLocalBasedCodeContext.java:142)
      at com.atlassian.servicedesk.internal.utils.context.ReentrantThreadLocalBasedCodeContext.runOutOfContext(ReentrantThreadLocalBasedCodeContext.java:94)
      at com.atlassian.servicedesk.internal.utils.context.CustomerContextServiceImpl.runOutOfCustomerContext(CustomerContextServiceImpl.java:61)
      at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.outOfCustomerContext(CustomerContextSettingFilter.java:174)
      at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilterImpl(CustomerContextSettingFilter.java:130)
      at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilter(CustomerContextSettingFilter.java:121)
      ... 4 filtered
      at com.atlassian.jwt.internal.servlet.JwtAuthFilter.doFilter(JwtAuthFilter.java:32)
      ... 8 filtered
      at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
      ... 4 filtered
      at com.atlassian.web.servlet.plugin.LocationCleanerFilter.doFilter(LocationCleanerFilter.java:36)
      ... 29 filtered
      at com.atlassian.jira.servermetrics.MetricsCollectorFilter.doFilter(MetricsCollectorFilter.java:25)
      ... 27 filtered
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
      at java.lang.Thread.run(Thread.java:745)

"Cannot attach file image.jpg: Unknown server error (500)."