[FOP-1840] [PATCH] Region-Body Column balancing incorrect if content is table with header

• Type: Improvement
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 1.0
• Fix Version/s: 2.2
• Component/s: layout/unqualified
• Environment: Operating System: All; Platform: PC
• External issue ID: 49801
• Assignee: fop-dev
• Reporter: a.kovacs
• Created: 23/Aug/10 05:56
• Updated: 11/Apr/17 11:23
• Resolved: 11/Apr/17 11:23

Description

To reproduce bug please do the following:
Use:
<fo:region-body region-name="PageBody" column-count="2" />

Fill the region-body with content like :
<fo:block span="none" > ...(content is table with header) ..
<fo:block span="all"> ... (one line (summary)) ..

If the content is made of normal blocks the columns are balanced before the span="all" summary line.
like:
123456 456789
234567 567890
345678 678901
Summary: 1234567890

If the content is a table without headers the columns are balanced correct.
like:
123456 456789
234567 567890
345678 678901
Summary: 1234567890

If the content is a table with header the columns are not balanced correct. (the right one is shorter.)
Header Header
123456 567890
234567 678901
345678
456789
Summary: 1234567890

The "computeDemerits()" algorithm is wrong in class "BalancingColumnBreakingAlgorithm".
The "fullLen" value is to short. Exactly the replicated header width is missing. In the "par" list the header is contained only once although the header is displayed in every column. (in the example twice)

Solution could be to place the header as many times in the "par" list as many columns exist, or to count the existing one header as many times as needed.