Uploading empty files to a Documents and Media DDM field throws errors

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 M4
• Fix Version/s: 7.0.0 M4
• Component/s: Documents & Media
• Labels: None
• Fix Priority: 4
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/23026

Steps to reproduce:

1. Add a Structure with a Documents and Media field
   • Add a Template based on that structure
2. Add a Web Content article based on that structure
   • Upload any file that has no data in it

Expected result:
User will be able to upload empty files, however unhelpful that may be.

Actual result:
UI throws a red message on the screen and the following console error is thrown:

21:28:27,877 ERROR [http-bio-8080-exec-27][render_portlet_jsp:132] null
java.lang.IllegalArgumentException: Input stream is null
        at com.liferay.portal.kernel.util.StreamUtil.transfer(StreamUtil.java:116)
        at com.liferay.portal.kernel.util.StreamUtil.transfer(StreamUtil.java:107)
        at com.liferay.portal.kernel.util.StreamUtil.transfer(StreamUtil.java:85)
        at com.liferay.portal.util.FileImpl.write(FileImpl.java:929)
        at com.liferay.portal.util.FileImpl.createTempFile(FileImpl.java:199)
        at com.liferay.portal.kernel.util.FileUtil.createTempFile(FileUtil.java:102)
        at com.liferay.portal.repository.capabilities.TemporaryFileEntriesCapabilityImpl.addTemporaryFileEntry(TemporaryFileEntriesCapabilityImpl.java:69)
        at com.liferay.portal.kernel.util.TempFileEntryUtil.addTempFileEntry(TempFileEntryUtil.java:82)
        at com.liferay.portlet.documentlibrary.service.impl.DLAppServiceImpl.addTempFileEntry(DLAppServiceImpl.java:426)
        at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:149)
        at com.liferay.portal.spring.transaction.DefaultTransactionExecutor.execute(DefaultTransactionExecutor.java:53)
        at com.liferay.portal.spring.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:55)
        at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:123)
        at com.liferay.portal.spring.aop.ChainableMethodAdvice.invoke(ChainableMethodAdvice.java:56)
        at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:123)
        at com.liferay.portal.spring.aop.ChainableMethodAdvice.invoke(ChainableMethodAdvice.java:56)
        at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:123)
        at com.liferay.portal.spring.aop.ServiceBeanAopProxy.invoke(ServiceBeanAopProxy.java:174)
        at com.liferay.portlet.documentlibrary.service.DLAppServiceUtil.addTempFileEntry(DLAppServiceUtil.java:279)
        at com.liferay.portlet.documentlibrary.action.EditFileEntryAction.addTempFileEntry(EditFileEntryAction.java:451)