package subfig interfering with caption setup of package caption

Question

Consider this example identified as a solution for remove colon in captions:

\documentclass{report}
%\usepackage{subfig}                                                                                                                                                                                        
\usepackage{graphicx}
\usepackage[latvian]{babel}
\usepackage{caption}
\captionsetup[figure]{labelsep=space}
\addto\captionslatvian{\renewcommand{\figurename}{att.}}
\begin{document}
\begin{figure}
  \includegraphics{example-image-a}
  \caption{Case of A.}
\end{figure}
\end{document}

The command

\captionsetup[figure]{labelsep=space}

fails once the line

%\usepackage{subfig}

is uncommented, i.e. the separator once again is :. How to solve?

Answer 1

The latvian.ldf redefines \@makecaption. So load subfig after babel (you don't need to load caption, subfig is doing it):

\documentclass{report}

\usepackage{graphicx}

\usepackage[latvian]{babel}
\usepackage{subfig}

\captionsetup{labelsep=space}
\addto\captionslatvian{\renewcommand{\figurename}{att.}}
\begin{document}
\begin{figure}\tracingmacros=1
  \includegraphics{example-image-a}
  \caption{Case of A.}
\end{figure}
\end{document}

Answer 2

You can replace \subfloat easily enough using a subfigure and a savebox. Admittedly this version does not implement the list option, but that can be done using xparse or \@ifnextchar[.

\documentclass{report}
\usepackage{graphicx}
\usepackage[latvian]{babel}
\usepackage{subcaption}
\captionsetup[figure]{labelsep=space}
\addto\captionslatvian{\renewcommand{\figurename}{att.}}

\newcommand{\subfloat}[2][\empty]% #1=caption (optional), #2=body
{\bgroup
  \sbox0{#2}% measure image
  \begin{subfigure}[b]{\wd0}
    \usebox0
    \ifx\empty#1\relax
    \else\caption{#1}
    \fi
  \end{subfigure}
\egroup}

\begin{document}
\begin{figure}
\subfloat[Case of A.]{\includegraphics{example-image-a}}
\end{figure}
\end{document}