Amend 207eaeee90

The upstream encoding needs to be updated after this routine
(see comment in OutputParams.h:183ff.)

(cherry picked from commit 2d95f8fc16)

src/output_latex.cpp

@@ -494,6 +494,9 @@ void TeXEnvironment(Buffer const & buf, Text const & text,
 
 	if (pit != runparams.par_end)
 		LYXERR(Debug::OUTFILE, "TeXEnvironment for paragraph " << par_begin << " done.");
+
+	// set upstream encoding
+	runparams_in.encoding = runparams.encoding;
 }