Prevent manual line break in lower title back

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+- Prevent line break in the lower back title if one added a manual line break
+  using `\\` to the title in order to layout it properly for the front title
+  page.
+
 ## [v4.3.1] – 2024–07–31
 
 ### Added

se2thesis.dtx

@@ -1409,12 +1409,18 @@
 %    \end{macrocode}
 %
 % \begin{macro}{\@lowertitleback}
-%   Afterwards, override the definition of \cs{@lowertitleback}.
+%   Afterwards, override the definition of \cs{@lowertitleback}.  To prevent
+%   line breaks in the title (that might be necessary to layout it properly on
+%   the front title page), we place a group around \cs{@title} and temporarily
+%   redefine \cmd{\\} to do nothing.
 %    \begin{macrocode}
 \renewcommand*{\@lowertitleback}{%
   \group_begin:
     \noindent\textbf{\@author}:\\
-    \emph{\@title}\\
+    \group_begin:
+      \let\\\relax
+      \emph{\@title}
+    \group_end:\\
     \tl_if_eq:NnT \l_@@_thesis_type_tl { bachelor }
       { \GetTranslation{Bachelor-thesis},~ }
     \tl_if_eq:NnT \l_@@_thesis_type_tl { master }