sw floattable: fix fly pos invalidation in follow anchor frames

The problem was that in case a row split moved the 2nd half of the row
to a new page, the follow fly frame had a wrong position (top left
corner of the page).

What happened was that the follow anchor (text frame) was not yet
positioned by the time the follow fly was positioned, and there was no
invalidation once the follow anchor got its position.

Fix the problem by improving SwTextFrame::MakePos(): it already had code
to invalidate the position of follow flys when the position of the
anchor changes, but it assumed that the flys of a follow anchor are in
the follow anchor, while in fact flys are always nominally anchored in
the master, so we didn't find the relevant fly frame and no invalidation
happened.

Once we use FindMaster() to look up the master and filter based on
FindAnchorCharFrame(), we find the relevant fly to invalidate and the
position is correct.

Change-Id: Ic485527bb9dd05b3d5aed383eb5fa1c4f9f6a76d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/147943
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

1 files changed, 13 insertions, 1 deletions

diff --git a/sw/source/core/text/frmform.cxx b/sw/source/core/text/frmform.cxx
index 74d1a7cec04e..b1e98d9771bc 100644
--- a/sw/source/core/text/frmform.cxx
+++ b/sw/source/core/text/frmform.cxx
@@ -342,8 +342,20 @@ void SwTextFrame::MakePos()
 {
     SwFrame::MakePos();
 
-    for (const auto& pFly : GetSplitFlyDrawObjs())
+    // Find the master frame.
+    const SwTextFrame* pMaster = this;
+    while (pMaster->IsFollow())
     {
+        pMaster = pMaster->FindMaster();
+    }
+    // Find which flys are effectively anchored to this frame.
+    for (const auto& pFly : pMaster->GetSplitFlyDrawObjs())
+    {
+        SwTextFrame* pFlyAnchor = pFly->FindAnchorCharFrame();
+        if (pFlyAnchor != this)
+        {
+            continue;
+        }
         // Possibly this fly was positioned relative to us, invalidate its position now that our
         // position is changed.
         pFly->InvalidatePos();