LaTeX: let \sphinxremovefinalcolon work also if no colon in input

doc/latex.rst

@@ -1498,6 +1498,16 @@ Macros
         \renewcommand\sphinxwarningtitle[1]{%
           \underline{\textbf{\sphinxremovefinalcolon{#1}}}\par
         }
+        \renewcommand{\sphinxnotetitle}[1]{%
+          \textit{\textbf{\sphinxremovefinalcolon{#1}}}\par\nobreak
+          % LaTeX syntax is complex and we would be better off using \hrule here.
+          {\parskip0pt\noindent}%
+          \raisebox{1ex}%
+             {\makebox[\linewidth]{\textcolor{sphinxnoteBorderColor}{\dotfill}}}
+          % It is complex to obtain nice vertical spacing for both a paragraph or
+          % a list following up; this set-up is better for a text paragraph next.
+          \par\vskip-\parskip
+        }
 
 - More text styling:
 

sphinx/texinputs/sphinxlatexstyletext.sty

@@ -19,15 +19,26 @@
 \let\sphinxerrortitle    \sphinxnotetitle
 \def\sphinxseealsotitle#1{\sphinxstrong{#1}\par\nopagebreak}
 %
-% A utility to remove a final colon
-% (one must be certain the semi-colon is there)
-\protected\def\sphinxremovefinalcolon #1{%
+% A utility to remove a final colon.  Removing last token is not easy in
+% LaTeX, and there are additional complications:
+% - some languages will make the : "active" in document body,
+% - the generic admonition ends up using "note", so for \sphinxnotetitle to
+%   use it safely, the utility has to allow an input not having any final colon.
+% - a bit far-fetched but maybe there is more than one colon inside the input
+%   (possible from a generic admonition title).
+% Hence the scary code.
+\def\sphinxremovefinalcolon#1{% #1 is the "active" : TeX token
+\protected\def\sphinxremovefinalcolon ##1{%
    % complications due to : possibly "active"
    \begingroup\ifnum\catcode`:=\active
-                    \lccode`~=`:\lowercase{\def\x##1~}{##1}%
-               \else\def\x##1:{##1}\fi
-   \expandafter\endgroup\x#1%
-}%
+                    \def\x####1#1\relax{####1}%
+               \else\def\x####1:\relax{####1}\fi
+   \expandafter\endgroup\x##1\relax
+   % trick to let \x work also if input ##1 has no ending colon
+   \@gobblefour#1\relax:\relax\relax\relax
+   }%
+}% end of wrapper to inject active :
+\begingroup\catcode`:\active\expandafter\endgroup\sphinxremovefinalcolon:
 % See doc/latex.rst for an example.
 
 % Some custom font markup commands.