From 27e68ed6a97a02f59c74309e9a7a9b2f4099705b Mon Sep 17 00:00:00 2001
From: Fredrik Ekre <fredrik.ekre@chalmers.se>
Date: Mon, 21 May 2018 14:49:18 +0200
Subject: [PATCH] only try the pdf -> png convert if the backend support
 application/pdf mime

---
 src/output.jl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/output.jl b/src/output.jl
index 3932d94b..ca1461c8 100644
--- a/src/output.jl
+++ b/src/output.jl
@@ -218,9 +218,10 @@ closeall() = closeall(backend())
 # ---------------------------------------------------------
 # A backup, if no PNG generation is defined, is to try to make a PDF and use FileIO to convert
 
+const PDFBackends = Union{PGFPlotsBackend,PlotlyJSBackend,PyPlotBackend,InspectDRBackend,GRBackend}
 if is_installed("FileIO")
     @eval import FileIO
-    function _show(io::IO, ::MIME"image/png", plt::Plot)
+    function _show(io::IO, ::MIME"image/png", plt::Plot{<:PDFBackends})
         fn = tempname()
 
         # first save a pdf file