Why is this way of highlight text in code listing not working with beamer class?

Question

This answer provides a nice solution to Highlight text in code listing while also keeping syntax highlighting which is improved in another answer. The point is the former works like a charm with the beamer class but, as shown by the following MCEs, not the latter (nothing is highlighted).

How to make the latter solution work with beamer?

(Note that other answers, e.g. this nice one, provide solutions that are working with beamer.)

Former answer which is working with beamer

\documentclass{beamer}
\usepackage{listings,xcolor,tikz}
\newcommand\bh{\tikz[remember picture]
  \node (begin highlight) {};
}
\newcommand\eh{\tikz[remember picture]
  \node (end highlight) {};
  \tikz[remember picture, overlay]
  \draw[yellow,line width=10pt,opacity=0.3] (begin highlight) -- (end
  highlight);
}


\begin{document}

\begin{frame}[fragile]
\bh abc bce bde bde \eh

\begin{lstlisting}[escapechar=@,language=SQL]
WHERE name=@\bh@UNION SELECT@\eh@
\end{lstlisting}
\end{frame}

\end{document}

Latter answer which is not working with beamer

\documentclass{beamer}

% required packages
\usepackage{atbegshi,ifthen,listings,tikz}

% change this to customize the appearance of the highlight
\tikzstyle{highlighter} = [
  yellow,
  line width = \baselineskip,
]

% enable these two lines for a more human-looking highlight
%\usetikzlibrary{decorations.pathmorphing}
%\tikzstyle{highlighter} += [decorate, decoration = random steps]

% implementation of the core highlighting logic; do not change!
\newcounter{highlight}[page]
\newcommand{\tikzhighlightanchor}[1]{\ensuremath{\vcenter{\hbox{\tikz[remember picture, overlay]{\coordinate (#1 highlight \arabic{highlight});}}}}}
\newcommand{\bh}[0]{\stepcounter{highlight}\tikzhighlightanchor{begin}}
\newcommand{\eh}[0]{\tikzhighlightanchor{end}}
\AtBeginShipout{\AtBeginShipoutUpperLeft{\ifthenelse{\value{highlight} > 0}{\tikz[remember picture, overlay]{\foreach \stroke in {1,...,\arabic{highlight}} \draw[highlighter] (begin highlight \stroke) -- (end highlight \stroke);}}{}}}

\begin{document}

\begin{frame}[fragile]
Works in \bh{}plain text too\eh{} (but not across line breaks).

\begin{lstlisting}[escapechar=@, language=SQL, basicstyle=\sffamily, columns=fullflexible]
SELECT name, password FROM users WHERE name='@\bh@' UNION SELECT "10", 1 #@\eh@';
\end{lstlisting}
\end{frame}

\end{document}

Answer 1

@marmots analysis of the problem was correct. The highlighting in the second example works perfectly fine, it is just below the background layer. If you change the background colour from its default white to empty you can see the highlighting:

\documentclass{beamer}

% required packages
\usepackage{atbegshi,ifthen,listings,tikz}

% change this to customize the appearance of the highlight
\tikzset{highlighter/.style={
  yellow,
  line width = \baselineskip,
}}

% enable these two lines for a more human-looking highlight
%\usetikzlibrary{decorations.pathmorphing}
%\tikzstyle{highlighter} += [decorate, decoration = random steps]

% implementation of the core highlighting logic; do not change!
\newcounter{highlight}[page]
\newcommand{\tikzhighlightanchor}[1]{\ensuremath{\vcenter{\hbox{\tikz[remember picture, overlay]{\coordinate (#1 highlight \arabic{highlight});}}}}}
\newcommand{\bh}[0]{\stepcounter{highlight}\tikzhighlightanchor{begin}}
\newcommand{\eh}[0]{\tikzhighlightanchor{end}}
\AtBeginShipout{\AtBeginShipoutUpperLeft{\ifthenelse{\value{highlight} > 0}{\tikz[remember picture, overlay]{\foreach \stroke in {1,...,\arabic{highlight}} \draw[highlighter] (begin highlight \stroke) -- (end highlight \stroke);}}{}}}

\setbeamercolor{background canvas}{bg=}

\begin{document}

\begin{frame}[fragile]
Works in \bh{}plain text too\eh{} (but not across line breaks).

\begin{lstlisting}[escapechar=@, language=SQL, basicstyle=\sffamily, columns=fullflexible]
SELECT name, password FROM users WHERE name='@\bh@' UNION SELECT "10", 1 #@\eh@';
\end{lstlisting}
\end{frame}

\end{document}