latex+dvips+gv: the left vertical bar of the frame vanishes at certain magnifications

[ghost]

Feeding

\documentclass{article}
\usepackage{mdframed}
\begin{document}
\begin{mdframed}
Test
\end{mdframed}
\end{document}

to latex followed by dvips results in the left vertical bar (and, with different contents, sometimes the upper bar) of the frame vanishing at certain magnifications of gv: 0.1, 0.125, 0.250, and 2. Here is what we see at the double zoom:

This particular view is specific to gv. As opposed to http://tex.stackexchange.com/questions/124539/mdframed-missing-half-the-frame, we do NOT always miss a half of the frame. Other viewers (e.g., okular) have issues at other sets of magnifications.

To compare with other methods of generating a frame,

\documentclass{article}
\usepackage{framed,mdframed}
\begin{document}
\begin{framed}Good\end{framed}
\noindent\fbox{\parbox{\dimexpr\textwidth-2\fboxsep-2\fboxrule}{Good}}
\begin{mdframed}Bad\end{mdframed}
\end{document}

yields in gv.

Who is the culprit: latex, mdframed, dvips or any of their combinations? Any fix, any remedies?

Crosspost: http://tex.stackexchange.com/questions/686574 .

[muzimuzhi]

I think it's a rendering issue. The bar is too thin to be rendered at certain magnification.