[LyX/master] Do not wrap forceTLR in \L with babel and unicode engines

[Juergen Spitzmueller]

commit 1e28965589bcf5ad85ed6d75ae2e59611989f78e
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sat Dec 24 09:20:02 2022 +0100

    Do not wrap forceTLR in \L with babel and unicode engines
    
    It does not seem to be needed, the \L macro is undefined, and there
    does not seem to be an alternative.
---
 src/Paragraph.cpp |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index 063bf32..8f5f6f3 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -1094,16 +1094,21 @@ void Paragraph::Private::latexInset(BufferParams const & bparams,
 	odocstream::pos_type const len = os.os().tellp();
 
 	if (inset->forceLTR(runparams)
+	    // babel with Xe/LuaTeX does not need a switch
+	    // and \L is not defined there.
+	    && (!runparams.isFullUnicode() || !runparams.use_babel)
 	    && running_font.isRightToLeft()
 	    // ERT is an exception, it should be output with no
 	    // decorations at all
 	    && inset->lyxCode() != ERT_CODE) {
-		if (runparams.use_polyglossia) {
+		if (runparams.use_polyglossia)
+			// (lua)bidi
 			os << "\\LRE{";
-		} else if (running_font.language()->lang() == "farsi"
-			   || running_font.language()->lang() == "arabic_arabi")
+		else if (running_font.language()->lang() == "farsi"
+			 || running_font.language()->lang() == "arabic_arabi")
 			os << "\\textLR{" << termcmd;
 		else
+			// babel classic
 			os << "\\L{";
 		close = true;
 	}