tdf#138518 sw: layout: avoid moving flys forward prematurely

(regression from b9ef71476fd70bc13f50ebe80390e0730d1b7afb
"tdf#134298 sw: layout: remove left-over page frame without content")

When updating the 3rd ToX, the change to remove empty page frames
causes one page frame to be deleted.

On the subsequent layout, things generally move backward, but there are
some fly-related hiccups; the first problem is visible on page 7.

Commit eb85de8e6b61fb3fcb6c03ae0145f7fe5478bccf
"sw: layout: if fly's anchor moves forward, move fly off SwPageFrame"
helps quite a bit, but not completely; now the first problem happens on
page 54, when SwTextFrame 1261 and its fly 3132 are formatted.

Frame 1261 moves forward to page 55, and then
SwObjectFormatterTextFrame::CheckMovedFwdCondition() returns true and so
SwMovedFwdFramesByObjPos::Insert() is called to prevent frame 1261 from
moving back to page 54.

But the reason why it moved forward is that there are 3 flys on page 54
that are anchored on frames in the next-chain of 1261, namely 1275,
1283 and 1284; if these flys weren't on the page then 1261 would fit.

While the move forward cannot be easily prevented in the situation, it's
possible to avoid the entry into the SwMovedFwdFramesByObjPos map,
by detecting that there are flys on the page that would should forward
*before* the current one does.

With this fix and the above mentioned commit to get the flys off the
page, frame 1261 will eventually move back to page 54 again.

Change-Id: I83e44d65a0b889a49a313b0cd8b08efce4c3afa7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/114478
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

0 files changed, 0 insertions, 0 deletions