[birt-dev] checkin: Fix Bugzilla bug 193886 NPE is thrown when preview e

["Hongchang Lin" <hlin@xxxxxxxxxxx>]

- Summary:Fix Bugzilla Bug 193886 NPE is thrown when preview external CSS style in ppt[1205]

- Bugzilla Bug (s) Resolved: 193886

- Description:
The NPE is caused by the background image in external CSS style can't be fetch.
Fix this possible NPE.

- Tests Description: Manual test and code review

- Notes to Build Team:

- Notes to Developers:

- Notes to QA:

- Notes to Documentation:

- Files Edited:

/org.eclipse.birt.report.engine.emitter.ppt/src/org/eclipse/birt/report/engine/emitter/ppt/PPTRender.java

- Files Added:

- Files Deleted:

 

Hongchang Lin