tex2lyx/Preamble.cpp: fix bug #9561

there were 2 issues:
- the body was not output to the Preamble
- the theorem module already defines a theorem. It must not be output to the preamble to avoid a redefinition error of LaTeX

update the test files accordingly

src/tex2lyx/Preamble.cpp

@@ -1684,13 +1684,22 @@ void Preamble::parse(Parser & p, string const & forceclass,
 			string const body = p.verbatim_item();
 			string const opt3 = p.getFullOpt();
 
-			add_known_theorem(name, opt1, !opt2.empty(),
-				from_utf8("\\newtheorem{" + name + '}' +
-				          opt1 + opt2 + '{' + body + '}' + opt3));
+			string const complete = "\\newtheorem{" + name + '}' +
+				          opt1 + opt2 + '{' + body + '}' + opt3;
+
+			add_known_theorem(name, opt1, !opt2.empty(), from_utf8(complete));
+
+			// we know that our theorem module already add automatically some
+			// theorem definition. They must not be output in the preamble to
+			// avoid LaTeX errors about redefinitions
+			if (complete == "\\newtheorem{thm}{\\protect\\theoremname}")
+				in_lyx_preamble = true;
+			else
+				in_lyx_preamble = false;
 
 			if (!in_lyx_preamble)
 				h_preamble << "\\newtheorem{" << name << '}'
-				           << opt1 << opt2 << '{' << '}' << opt3;
+				           << opt1 << opt2 << '{' << body << '}' << opt3;
 		}
 
 		else if (t.cs() == "def") {

src/tex2lyx/test/test-modules.lyx.lyx

@@ -5,8 +5,16 @@
 \origin roundtrip
 \textclass amsart
 \begin_preamble
+\numberwithin{equation}{section} %% Comment out for sequentially-numbered
+\numberwithin{figure}{section} %% Comment out for sequentially-numbered
+\providecommand{\theoremname}{Theorem}
+\theoremstyle{plain}
+\newtheorem{lem}[thm]{Lemma}
+
 \usepackage{babel}
 
+
+
 \end_preamble
 \use_default_options false
 \begin_modules

src/tex2lyx/test/test-modules.tex

@@ -1,19 +1,14 @@
-%% LyX 1.6.1 created this file.  For more info, see http://www.lyx.org/.
-%% Do not edit unless you really know what you are doing.
 \documentclass[oneside,english]{amsart}
 \usepackage[T1]{fontenc}
 \usepackage[latin9]{inputenc}
 \usepackage{amsthm}
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
 \numberwithin{equation}{section} %% Comment out for sequentially-numbered
 \numberwithin{figure}{section} %% Comment out for sequentially-numbered
 \providecommand{\theoremname}{Theorem}
 \theoremstyle{plain}
-\theoremstyle{plain}
 \newtheorem{thm}{\protect\theoremname}
-  \theoremstyle{plain}
-  \newtheorem{lem}[thm]{Lemma}
+\theoremstyle{plain}
+\newtheorem{lem}[thm]{Lemma}
 
 \usepackage{babel}