[LyX/master] Fix #11520 Wrong inpute encoding when master and child use different setting.

[Guenter Milde]

On 2019-12-09, Scott Kostyshak wrote:
> On Mon, Mar 18, 2019 at 06:13:40PM +0100, Günter Milde wrote:
>> commit 553bebc3550f932ca3c25bbd4ae3905b60026b3c
>> Author: Günter Milde <milde at lyx.org>
>> Date:   Mon Mar 18 18:16:40 2019 +0100

>>     Fix #11520 Wrong inpute encoding when master and child use different setting.
>> ---

> I get a crash starting with this commit. To reproduce:

>   1. Save both of the attached files of this email to the same directory.
>   2. In LyX, turn instant preview to "on" in Preferences.
>   3. Open mwe.lyx.

> LyX gives a SIGSEGV on opening the file.

> Attached is a patch. I don't know if it makes sense. It attempts to keep
> the desired behavior of 553bebc3 except when oldEnc is 0. Günter can you
> have a look?

The patch looks good to me.

Thank you

Günter

> [-- Skipped Type: application/x-lyx, Filename: child_of_mwe.lyx --]
> [-- Skipped Type: application/x-lyx, Filename: mwe.lyx --]
> [-- Type: text/x-diff, Encoding: quoted-printable, Filename: 0001-Fix-crash-due-to-encoding-issues-with-child-doc.patch --]

> From 1f4164fbb12e78b5d2d9a579e5b75b980a035b80 Mon Sep 17 00:00:00 2001
> From: Scott Kostyshak <skostysh at lyx.org>
> Date: Sun, 8 Dec 2019 19:14:38 -0500
> Subject: [PATCH] Fix crash due to encoding issues with child doc

> This crash occured starting with 553bebc3, and can be triggered when
> preview is enabled both in preferences and in a child document
> inset. For a minimal example, see my email sent to lyx-devel on
> 2019-12-08.

> This fix restores behavior to before that commit for the case when
> oldEnc is 0.
> ---
>  src/insets/InsetInclude.cpp | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)

> diff --git a/src/insets/InsetInclude.cpp b/src/insets/InsetInclude.cpp
> index 3cf318906f..1bd1c5ba02 100755
> --- a/src/insets/InsetInclude.cpp
> +++ b/src/insets/InsetInclude.cpp
> @@ -848,8 +848,11 @@ void InsetInclude::latex(otexstream & os, OutputParams const & runparams) const
>  		Language const * const oldLang = runparams.master_language;
>  		// If the master uses non-TeX fonts (XeTeX, LuaTeX),
>  		// the children must be encoded in plain utf8!
> -		runparams.encoding = masterBuffer->params().useNonTeXFonts ?
> -			encodings.fromLyXName("utf8-plain") : oldEnc;
> +		if (masterBuffer->params().useNonTeXFonts)
> +			runparams.encoding = encodings.fromLyXName("utf8-plain");
> +		else if (oldEnc)
> +			runparams.encoding = oldEnc;
> +		else runparams.encoding = &tmp->params().encoding();
>  		runparams.master_language = buffer().params().language;
>  		runparams.par_begin = 0;
>  		runparams.par_end = tmp->paragraphs().size();