Load inputenc after babel with Thai.

"thai.ldf" breaks "inputenc" by changing catcodes.
Loading "inputenc" after "babel" allows a workaround.

autotests/export/latex/en-th_language-default.lyx

@@ -6,7 +6,7 @@
 \origin unavailable
 \textclass article
 \begin_preamble
-\AtBeginDocument{\usepackage{fonts-tlwg}}
+
 \end_preamble
 \use_default_options true
 \maintain_unincluded_children false
@@ -27,7 +27,7 @@
 \use_microtype false
 \use_dash_ligatures true
 \graphics default
-\default_output_format default
+\default_output_format pdf2
 \output_sync 0
 \bibtex_command default
 \index_command default
@@ -84,7 +84,7 @@
 \begin_body
 
 \begin_layout Subsection*
-Thai
+Test workaround for Thai language
 \end_layout
 
 \begin_layout Standard

autotests/export/latex/en-th_utf8.lyx

@@ -5,18 +5,15 @@
 \save_transient_properties true
 \origin unavailable
 \textclass article
-\begin_preamble
-\AtBeginDocument{\usepackage{fonts-tlwg}}
-\end_preamble
 \use_default_options true
 \maintain_unincluded_children false
 \language english
 \language_package default
 \inputencoding utf8
 \fontencoding auto
-\font_roman "lmodern" "FreeSerif"
+\font_roman "lmodern" "Norasi"
-\font_sans "default" "FreeSans"
+\font_sans "default" "Garuda"
-\font_typewriter "default" "FreeMono"
+\font_typewriter "default" "Tlwg Mono"
 \font_math "auto" "auto"
 \font_default_family default
 \use_non_tex_fonts false
@@ -84,7 +81,7 @@
 \begin_body
 
 \begin_layout Subsection*
-Thai
+Test workaround for Thai language
 \end_layout
 
 \begin_layout Standard
@@ -203,7 +200,11 @@ uc/lccode changes prevent up/downcasing of high-bit characters
 \begin_inset Newline newline
 \end_inset
 
-(lösen → 
+(lösen 
+\begin_inset Formula $→$
+\end_inset
+
+ 
 \begin_inset ERT
 status open
 
@@ -227,7 +228,11 @@ status open
 
 \end_inset
 
-, LÖSEN → 
+, LÖSEN 
+\begin_inset Formula $→$
+\end_inset
+
+ 
 \begin_inset ERT
 status open
 

development/autotests/ignoredTests

@@ -171,4 +171,4 @@ lyx2lyx/export/latex/.*
 export/export/latex/.*(lyx..|xhtml)
 
 # don't test with non-TeX fonts:
-export/export/latex/en-th_(LTH|language-default).*systemF
+#export/export/latex/en-th_(LTH|language-default).*systemF

development/autotests/invertedTests

@@ -74,7 +74,7 @@ export/templates/Articles/International_Union_of_Crystallography.*_pdf4_systemF
 export/templates/Articles/R_Journal_(dvi3|pdf[45])_systemF
 #export/templates/Articles/Kluwer_.*_systemF
 
-# Babel and fontenc not fails for some supported languages
+# Babel and fontenc fails for some supported languages
 # * check BabelPremble definitions in lib/languages
 # * fails also due to #11522, see "lyxbugs" below.
 export/export/latex/supported-languages_.*_systemF
@@ -332,14 +332,6 @@ export/.*/he/.*_texF
 # See comment in unreliableTests
 export/export/latex/uk-babel-date-missing-chars-with-ascii_pdf5_texF
 
-# Thai
-# babel-thai globally changes catcodes for high-bit chars
-# which prevents parsing of utf8 with vanilla inputenc (utf8x works)
-# see also unreliable.wrong_output and unreliable.varying_versions
-export/export/latex/en-th_utf8_(dvi|pdf[23]?|pdf4_texF)
-# luainputenc fails with TL19:
-export/export/latex/en-th_language-default_(dvi3|pdf5)_texF
-
 
 # ================================================
 Sublabel: externalissues

development/autotests/unreliableTests

@@ -143,12 +143,6 @@ export/templates/Articles/American_Astronomical_Society_.*
 export/templates/Articles/Association_for_Computing_Machinery_pdf[45]_texF
 
 
-# Thai
-# Babel-thai globally changes catcodes for high-bit chars
-# which clashes with vanilla inputenc (utf8x and 8-bit input encodings and
-# luainputenc work with TL17 but luainputenc fails with TL19):
-export/export/latex/en-th_language-default_(dvi3|pdf5)_texF
-
 Sublabel: wrong_output
 ######################
 # Export does not fail but the resulting document has errors.
@@ -173,15 +167,6 @@ export/export/latex/es_auto-legacy_texF
 export/export/latex/uk-babel-date-missing-chars-with-ascii_.*_texF
 export/doc/uk/Intro_.*_texF
 
-# Thai
-# Babel-thai globally changes catcodes for high-bit chars
-# which prevents parsing of utf8 with vanilla inputenc (utf8x works).
-# see also invertedTests
-export/export/latex/en-th_language-default_(dvi|pdf).?
-export/export/latex/en-th_utf8_(dvi|pdf).*
-#
-# only ASCII characters in DVI (LuaTeX) with non-TeX fonts:
-export/export/latex/en-th_utf8_dvi3_systemF
 
 # LyX issues
 # **********

lib/languages

@@ -1366,25 +1366,25 @@ Language thai
 	FontEncoding     LTH
 	DateFormats      "dd MMMM yyyy|d MMM yyyy|dd/MM/yyyy"
 	LangCode         th_TH
+	# The first workaround requires loading inputenc after babel
+	# (cf. BufferParams.cpp):
 	PostBabelPreamble
-	  % Restore \coyright definition corrupted by lthenc.def
-	  \DeclareRobustCommand{\copyright}{%
-	    \ifmmode{\nfss@text{\textcopyright}}\else\textcopyright\fi}
-	  \DeclareTextSymbol{\textcopyright}{LTH}{8}
 	  % Restore catcodes changed by thai.ldf (active characters required for inputenc)
 	  \@tempcnta=161%
 	  \@whilenum\@tempcnta<252\do{%
 	    \catcode\@tempcnta=13
 	    \advance\@tempcnta\@ne
 	  }%	  
+	  % Restore \coyright definition corrupted by lthenc.def
+	  \DeclareRobustCommand{\copyright}{%
+	    \ifmmode{\nfss@text{\textcopyright}}\else\textcopyright\fi}
+	  \DeclareTextSymbol{\textcopyright}{LTH}{8}
+          % set up Thai fonts as substitue for the default families
+          \usepackage{substitutefont}
+          \substitutefont{LTH}{\rmdefault}{norasi}
+          \substitutefont{LTH}{\sfdefault}{garuda}
+          \substitutefont{LTH}{\ttdefault}{ttypist}
 	EndPostBabelPreamble
-	# Fixme: load font package?
-	# +1 support for font attributes in thai emphasizing etc.
-	# -1 forces ComputerModern as "non-thai" font
-	# TODO: set norasi as surrogate font for LTH (substitutefont.sty)
-	# PostBabelPreamble
-	#   \usepackage{fonts-tlwg}
-	# EndPostBabelPreamble
 End
 
 # not supported by babel

src/BufferParams.cpp

@@ -1801,10 +1801,11 @@ bool BufferParams::writeLaTeX(otexstream & os, LaTeXFeatures & features,
 	if (features.mustProvide("pmboxdraw"))
 		os << "\\usepackage{pmboxdraw}\n";
 	
-	// FIXME: In any document containing text in Thai language, 
-	// we must load babel before inputenc (see lib/languages).
 	// handle inputenc etc.
-	writeEncodingPreamble(os, features);
+	// (In documents containing text in Thai language, 
+	// we must load inputenc after babel, see lib/languages).
+	if (!contains(features.getBabelPostsettings(), from_ascii("thai.ldf")))
+	  writeEncodingPreamble(os, features);
 
 	// includeonly
 	if (!features.runparams().includeall && !included_children_.empty()) {
@@ -2288,6 +2289,11 @@ bool BufferParams::writeLaTeX(otexstream & os, LaTeXFeatures & features,
 		                          !lyxrc.language_global_options)) + '\n';
 		os << features.getBabelPostsettings();
 	}
+	// In documents containing text in Thai language, 
+	// we must load inputenc after babel (see lib/languages).
+	if (contains(features.getBabelPostsettings(), from_ascii("thai.ldf")))
+	  writeEncodingPreamble(os, features);
+
 	if (features.isRequired("bicaption"))
 		os << "\\usepackage{bicaption}\n";
 	if (!listings_params.empty()