[birt-dev] CheckIn:Fix bugzilla Bug 191876All the columns are doubled wh

["Mingxia Wu" <mwu@xxxxxxxxxxx>]

- Summary:
Fix bugzilla Bug 191876 All the columns are doubled when join two data set extended from library [01]

- Bugzilla Bug (s) Resolved:
191876

- Description:

The joint dataset now retrieves its subdataset’s metadata from its cache metadata. Fix it!

- Tests Description:

- Notes to Build Team:

- Notes to Developers:

- Notes to QA:  

- Notes to Documentation:  

- Files Edited:
"/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/dataset/ExpressionValueCellEditor.java" "/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/dataset/ResultSetPreviewPage.java" "/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/dataset/JointDataSetPage.java" "/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java"

- Files Added:

- Files Deleted