tdf#86630 sw page number wizard: avoid crash when no GetCurrFrame

The steps to get the crash were:
-create a header (and leave the cursor in the header)
-use the wizard to create a non-mirrored footer

I had seen this crash happening occassionally during development,
but hadn't yet identified the exact steps to consistently reproduce.
Thanks to QA who tracked that down.

Although it looks/feels like a hack, it actually works amazingly well.
The simple act of SetCursorInHdFt "fixes" GetCurrFrame/Get*PageNum,
but we can't always use that because we don't know whether we
are on an odd or even or first page when we start, so Goto*Text
is the best when non-mirroring.

Change-Id: I0e2f28d9c8fd2d1a10afede885b525c42ed08af4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/151345
Tested-by: Jenkins
Reviewed-by: Justin Luth <jluth@mail.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/sw/source/uibase/shells/textfld.cxx b/sw/source/uibase/shells/textfld.cxx
index 63d0db3c0b37..d3b3d6853dff 100644
--- a/sw/source/uibase/shells/textfld.cxx
+++ b/sw/source/uibase/shells/textfld.cxx
@@ -1134,8 +1134,14 @@ FIELD_INSERT:
                 bool bInHF = false;
                 bool bSkipMirror = true;
                 size_t nEvenPage = 0;
-                if (bCreateMirror)
+                if (bCreateMirror || !rSh.GetCurrFrame())
                 {
+                    // Come here if Currframe can't be found, otherwise Goto*Text will crash.
+                    // Get*PageNum will also be invalid (0), so we have no idea where we are.
+                    // (Since not asking for mirror, the likelihood is that the bHeader is shared,
+                    // in which case it doesn't matter anyway, and we just hope for the best.)
+                    // Read the code in this block assuming that bCreateMirror is true.
+
                     // There are enough pages that there probably is a valid odd page.
                     // However, that is not guaranteed: perhaps the page style switched,
                     // or a blank page was forced, or some other complexity.
@@ -1173,9 +1179,6 @@ FIELD_INSERT:
                 }
                 else
                 {
-                    // CurrFrame is lost when mirror is created. Goto*Text crashes if no CurrFrame
-                    assert(rSh.GetCurrFrame()); // not guaranteed, but normally assumed
-
                     if (bHeader)
                         bInHF = rSh.GotoHeaderText();
                     else