[LyX/master] Fix another old outliner bug (#9375)

[Juergen Spitzmueller]

commit 8fd1aaa46ea85dde9a0b19b427b72b406605a4d2
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Wed Feb 22 16:33:37 2023 +0100

    Fix another old outliner bug (#9375)
    
    Parts, chapters and sections have different LabelTypes, but this does
    not mean they cannot be transformed into each other while doing
    OUTLINE_IN/OUT
    
    Not sure why the labeltype check is here anyway, but let's keep it.
---
 src/Layout.h  |    5 +++++
 src/Text3.cpp |    6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Layout.h b/src/Layout.h
index 6efc512..6581155 100644
--- a/src/Layout.h
+++ b/src/Layout.h
@@ -292,6 +292,11 @@ public:
 			|| labeltype == LABEL_CENTERED
 			|| labeltype == LABEL_BIBLIO;
 	}
+	bool isNumHeadingLabelType() const {
+		return labeltype == LABEL_ABOVE
+			|| labeltype == LABEL_CENTERED
+			|| labeltype == LABEL_STATIC;
+	}
 	///
 	bool addToToc() const { return add_to_toc_; }
 	///
diff --git a/src/Text3.cpp b/src/Text3.cpp
index 148b1d4..d077dde 100644
--- a/src/Text3.cpp
+++ b/src/Text3.cpp
@@ -570,11 +570,11 @@ static void outline(OutlineOp mode, Cursor & cur, Text * text)
 				DocumentClass const & tc = buf.params().documentClass();
 				int const newtoclevel =
 					(mode == OutlineIn ? toclevel + 1 : toclevel - 1);
-				LabelType const oldlabeltype = start->layout().labeltype;
 
 				for (auto const & lay : tc) {
-					if (lay.toclevel ==  newtoclevel &&
-						 lay.labeltype == oldlabeltype) {
+					if (lay.toclevel == newtoclevel
+					    && lay.isNumHeadingLabelType()
+					    && start->layout().isNumHeadingLabelType()) {
 						start->setLayout(lay);
 						break;
 					}