Nested tables not respecting table separator specifications

[gkholman]

Specifying no separators in a table works fine:

Nesting that very same table in another table reveals the separators without any change to the markup:

Simple test files here:
table-separators-20241006.zip

[larsga]

In terms of the WordML markup, all three tables (1 in simple, 2 in the nested case) have the following:

<w:tblBorders>
  <w:top w:val="none" w:sz="8" w:space="0" w:color="auto"/>
  <w:left w:val="none" w:sz="8" w:space="0" w:color="auto"/>
  <w:bottom w:val="none" w:sz="8" w:space="0" w:color="auto"/>
  <w:right w:val="none" w:sz="8" w:space="0" w:color="auto"/>
  <w:insideH w:val="none" w:sz="0" w:space="0" w:color="auto"/>
  <w:insideV w:val="none" w:sz="0" w:space="0" w:color="auto"/>
</w:tblBorders>

However, the innermost table in the nested example has the above inside a <w:tblPr> element, then followed by a second <w:tblPr>, which contains:

<w:tblBorders>
  <w:top w:val="single"/>
  <w:left w:val="single"/>
  <w:bottom w:val="single"/>
  <w:right w:val="single"/>
  <w:insideH w:val="single"/>
  <w:insideV w:val="single"/>
</w:tblBorders>

So, apparently, the innermost table has an extra set of table properties in addition to the set of properties that Wordinator probably adds.

Next up, look at the code.

[larsga]

The problem somehow has to be that nested tables end up with two sets of table properties, even though according to the API that shouldn't really be possible. There is a CTTbl.addNewTblPr() method, though, and it seems like that potentially could end up created more than one tblPr element.

And, indeed, when we create nested tables we do it like this:

	              CTTbl ctTbl = cell.getCTTc().addNewTbl();
	              ctTbl = cell.getCTTc().addNewTbl();
	              CTTblPr tblPr = ctTbl.addNewTblPr(); // 1
	              tblPr.addNewTblW(); // 2

	              XWPFTable nestedTable = new XWPFTable(ctTbl, cell);

The lines marked 1 and 2 are the problem. If I take those out we get only one tblPr and the table is rendered correctly. The question then becomes, why are those lines there?

I note that in my original PR line 2 wasn't there, but line 1 was. If we have just line 1 the testNestedTableWidth test crashes with an NPE when it tries to set the table width.

So why did the original code create the table properties object before creating the table? Maybe because the solutions on StackOverflow have it? I guess probably it just got copied in for no good reason.

[larsga]

Pull request 158 solves this. We have tested it internally and not found any issues, so it should be safe to merge.